
Bookyjt 

Copyright ]^° 



CQEOUGHTOEFOSIC 






Steam Heating 



WARREN WEBSTER & GO, 

CAMDEN, NEW JERSEY 



STEAM HEATING v 



/y y^- 



A Manual of Practical Data 

Compiled by 

THE .GENERAL ENGINEERING COMMITTEE 

OK 

WARREN WEBSTER & COMPANY 

w 
JOHN A. SERRELL, Advisory Engineer 



Published by 

WARREN WEBSTER & COMPANY 

CAMDEN, N.J. 



First Edition, May, 1921 
Copyrighted 1921 by Warren Webster & Company 



Price $3.00 Net 






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MAY 23 1921 


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CONTENTS 

Chapter Page 

I The Elements of a Steam Heating System 000 

II Basic Data Required for the Design of Heating Systems 00 

III Heat Losses — Table of Factors 00 

IV Air Infiltration 00 

V Method of Computation of Heat Losses 00 

VI Selection and Sizing of Radiation 00 

VII Ventilation Problems as They AiFect the Design pf Steam Heating Systems . . 00 

VIII Chimneys — For Househeating Boilers; for Power Boilers 00 

IX Boilers 00 

X Selection of the Proper Type of Webster Heating System 00 

XI Pipe Sizes for Webster Systems 00 

XII Critical Flow of Steam Through Branch Run-outs 00 

XIII Capacities and Ratings of Traps and Valves 00 

XIV Vacuum Pumps and Auxiliary Equipment 00 

XV Application of Webster Systems to Slashers, Paper and Cloth Calenders, etc. 00 

XVI Application of Webster Systems to Evaporators, Vacuum Pans, etc 00 

XVII Application of Webster Systems to Lumber Kilns, etc 00 

XVIII Application of Webster Systems to Railroad Terminals and Steamship Piers 00 

XIX Application of Webster Systems to Sterilizers, Cooking Kettles, etc 00 

XX Application of Webster Systems to Greenhouses 00 

XXI Laboratory Tests 00 

XXII Installation Details 00 

XXIII Webster System Apparatus 00 

XXIV Specifications for Webster Systems 00 

XXV Webster Sylphon Attachments 00 

XXVI Webster Feed-water Heaters 00 

XXVII Miscellaneous Data and Tables 00 



FOREWORD 

THE subject of Heating and Ventilation has been covered broadly in 
many handbooks that are available for reference, but there has been 
a demand also for a book of information confined exclusively to Steam 
Heating and covering that field in all necessary detail. 

Steam Heating is therefore the one topic of this volume and the editors 
have aimed to cover the subject witli comprehensive data, arranged in such 
convenient and useful form as will best meet the needs of technical men in 
the engineering and contracting fields. 

The information given is authentic, being based upon actual practice 
and largely upon the experience of Warren Webster & Company, who, as 
pioneers, have specialized for more thaii thirty years in the effective use of 
steam for all heating pm"poses. Many of the designs and methods originated 
by this firm are now the recognized service standards. 

Special articles and helpful suggestions have been contributed by John 
A. Serrell, by the General Engineering Committee, and by John B. Dobson, 
Ralph T. Coe, William Roebuck, Russell C. Brown, William F. Bilyeu and 
other members of the Warren Webster & Company organization. 

"Steam Heating" offers the best thought of this organization, and as 
part of Webster Service is intended to be of real value throughout the pro- 
fession. The observance of good judgment and painstaking care in following 
its teachings wiU do much toward obtaining creditable and satisfactory 
results. 

If further explanations, additional information or helpful co-operation 
are desired, the Engineers and Service Men in the branch offices of Warren 
Webster & Company throughout the country are always available for 
consultation and assistance. 

General Engineering Committee of Warrfen Webster & Company 

William M. Tread well, Chairman 
Sidney E. Fenstermaker Harry M. Miller 
J. Logan Fitts Rudolph G. Rosenbach 



CHAPTER I 
Elements of Steam Heating 

THE purpose of a heating system is to warm the interior of a structure 
to a desired degree of temperature and to maintain this condition 
against a lower exterior degree. It is usual to assume the exterior 
temperature to be the average minimum expected in the locality. 

To warm the interior and to maintain a given temperature, heat is 
required to replace that which is absorbed by the contents and that trans- 
mitted through the structure to the exterior. 

Th':^ unit measure of heat in English-speaking countries is the British 
thermal unit, which is the heat necessary to raise the temperature of one 
pound of water from 39 to 40 deg. fahr. This is commonly known as B.t.u., 
or heat unit. 

The quantity of heat required to raise the temperature of a given 
weight of a substance through one deg. fahr. as compared with the quantity 
of heat required to raise the same weight of water from 62 deg. to 63 deg. 
fahr. is called the specific heat of that substance. (See Table 27-00, page 00.) 

The heat content, or quantity of heat per degree of a given mass of a 
substance, is the product of its specific heat and its weight in pounds. 

The rate at which initial heat is required to raise the temperature of a 
cold structure and its contents to the desired degree in a given time may 
be much greater than that necessary to maintain the required temperature 
after initial heating, or warm'ng up, has been accomplished. 

The greater the length of time permitted for initial warming, the less 
difference there will be between the heat requirement per unit of time during 
initial he a Ling and that required during subsequent maintenance. 

Heal lo jses by transmission through various forms of building structure 
have been a certained with more or less accuracy, and much information on 
this subject has been published from time to time. These data are being 
constantly improved as new forms of construction appear. 

The princpal discrepancies between published data on transmission are 
probably due mainly to various allowances which have been included for 
infiltration. Infiltration, or air leakage, should be considered independently 
of structural transmission. 

Local differences in workmanship and material of structure, as well as 
errors in observation, have further contributed to discrepancies, and in 
many instances the results of tests observed at one temperature difference 
have been reduced by direct proportion to a " per-degree-difference " basis. 

Until recently it has not been generally recognized that this last-men- 
tioned basis is in error, in that it is likely to give too high a rate of heat loss 
for smaller temperature difference and too low a rate for larger temperature 
difference than that existing during the test. 

The heat loss factors in Chapter 3 are based upon experience with vari- 
ous substances used in construction under average conditions at a difference 

1— ] 



of 70 deg. fahr. between interior and exterior temperatures. Factors for 
other temperature differences are stated as percentages of the 70 deg. normal. 
The effects of exposure and of varying wind velocities are separately con- 
sidered as losses due to infiltration. 

In order to determine the amount of heat required it is necessary to 
determine : 

First: The lowest temperature to which the interior will fall, that is, 
the "initial" temperature; and the temperature which it is desired shall be 
maintained within the enclosure, or the "maintained" temperature; 

Second: The time period in which it is required that the structure and 
its contents must be raised from initial to maintained temperatm"e; 

Third: The nature and the weight of the building and its contents 
(especially if large quantities of glass, metal or water are included) ; 

Fourth: The minimum exterior temperature; 

Fifth: The direction of the prevailing cold winds, and their anticipated 
velocities ; 

Sixth: The construction of the enclosure; 

Seventh: The topography of the site, and other local peculiarities. 

The heat transmitted hourly through the structure at a temperature 
difference between maintained interior and minimum exterior temperatures, 
plus the heat required to warm the infiltrated air through the same difference 
of temperature, gives the hourly maximum heat requirement during main- 
tenance. In Chapters 3 and 4 these two causes for heat requirements are 
further discussed. 

During initial heating or "warming up," heat units in addition to those 
required for maintenance must be supplied to raise the temperature of the 
structure and its contents of air and stored materials from their initial 
temperature to the desired temperature. 

In practice the heat absorbed by the structure and its stored materials 
is usually neglected, as the error is small. However, if the interior walls or 
columns are massive, or if the contents of the building include large quan- 
tities of materials with high specific heats, such as iron, steel, water, glass, 
etc., heat absorption of these must be taken into account. 

In almost all cases the heat required to raise the air contents of the 
enclosure from the initial to the maintained temperature must be considered. 

After determining the amount of heat required to warm the various 
substances during initial heating, the hourly rate at which this additional 
heat must be supplied during initial heating is obtained by multiplying this 
heat quantity by the reciprocal of the warming-up period in hours. 

A.pplications of the problem of determining the heat requirements will 
be found in Chapter 5. 

Where the heating requirements for warming-up are large compared 
with those for maintenance, the radiation necessary for the warming-up 
requirements and consequently the heat emitted will be correspondingly 

1—2 



excessive during maintenance. It is often advisable to increase the length 
of the warming-up period first allowed in order to reduce this excess radiation. 

Having estimated the total hourly heat requirement, the next consider- 
ation is the proper proportioning and distribution of radiating surfaces 
throughout the enclosure for obtaining the desired heating effect from the 
circulation of a fluid of higher temperature. 

In the following chapters the fluid considered for conveying heat is 
steam at pressures slightly above that of the atmosphere. The high thermal 
value, or B.t.u. per pound, of steam and the convenience with which it can 
be utihzed by means of commercial boilers, radiating surfaces, pipe and fit- 
tings and the special apparatus of the Webster System, has demonstrated 
the superiority of steam at low initial pressures for the great majority of 
installations. 

The radiating surfaces, or radiation, normaUy used in low-pressure 
steam heating to transmit heat from steam to the enclosure to be warmed, 
are of two general classes — Direct and Indirect — each of which has many 
specific sub-divisions. 

Direct radiation, properly classified, comprises only those arrangements 
of radiating surface which are located directly in the space to be heated. 

Radiation which is not wholly exposed in the space to be heated is 
termed indirect radiation. Units which are concealed under window boxes, 
or in housings having an air inlet near the floor line and a heated air outlet 
above the radiation, or which are enclosed in casings outside of the space 
to be heated and which have a cool air inlet from any source and a warm 
air connection to convey by heated air the necessary heat units to the 
space to be heated are examples of this type of radiation. 

Until recently the circulation of air for indirect heating by the method 
last mentioned was induced entirely by the difference in weight of the air 
columns before and after coming into contact with the enclosed radiating 
surface. Present usage designates such surfaces as indirect, distinguishing 
them from surfaces used in the later development, where additional circu- 
lating velocity is imparted mechanically by a fan or blower. Where mechan- 
ical means are used these surfaces are now designated as blower or fan-blast 
surface. 

Certain forms of radiating surfaces exposed in a room and so arranged 
with dampers and ducts that air wholly from the room or partly from 
without may be used to convey heat from the surface of the radiator to the 
room, are called direct-indirect surfaces. 

The rate of heat-flow through radiating surfaces from a given interior 
to a given exterior temperature varies not only with all classes of radiation 
but with all sub-divisions of those classes. This is due mainly to variation 
in convection, that is, in the facility for absorption of heat from the outer 
surface into the surrounding medium, and in a lesser degree, to the dis- 
persion of radiant heat. So great is this variation that, under similar 
conditions of location and temperature difference, and even in the simplest 
form of direct radiation, a low, narrow radiator will give ofi^ 40 per cent, 
more heat per square foot of radiation liian one that is extremely high and 
wide. 

1—3 



The term "square feet of radiation," therefore, means nothing specific 
and should not be used indiscriminately for sizing boilers, mains, or other 
apparatus in the heating system. 

The type of rad.'ating surface for the local conditions, heat require- 
ments and architecture, having been selected and placed, the proper size of 
radiating units should be determined. For this purpose the information on 
heat emission of various types of radiation, Chapter 6, will be found useful. 

The pipes which convey the heating fluid from its source to the radiating 
surfaces are termed supply mains. Those conveying the products of con- 
densation from the radiating surfaces to the point of disposal are termed 
return mains. The vertical parts of these mains are usually called risers, 
to distinguish them from horizontal runs. Risers, in turn, are classified by 
direction of flow, as up-feed or doivn-feed risers. The small branches to 
individual units of radiation are known as run-outs ; those supplying several 
units as branches, and those conveying all of the heating medium are usually 
termed trunk mains. 

The flow of the heat-carrying medium is always toward a lower pressm-e, 
and if the medium is steam confined in pipes or ducts sealed from the atmos- 
phere, the arbitrary dividing line conventionally drawn between "pressure" 
and "vacuum" does not enter. The problem involves only heat content, 
density, difference in pressure, condensation and friction. 

If the lowest terminal pressure in the system is that of the atmosphere 
as in an open-return line or modulation system, the initial pressure must be 
somewhat above the atmosphere. The amount of pressure above the atmos- 
phere depends largely upon the friction which must be overcome in the 
piping and upon the pressure necessary to give the steam its initial velocity. 
If, however, a terminal pressure lower than that of the atmosphere is mechan- 
ically mamtained, as in vacuum systems, the initial pressure may be above, 
at or below that of the atmosphere as best meets the local conditions. 

Vacuum system practice, with few exceptions, demands that a steam 
pressure equal to that of the atmosphere be maintained in the run-outs 
most distant from the source of steam supply, in order to avoid the air 
infiltration that would otherwise probably occur through minute leaks. 
This terminal pressure requires an initial pressure higher in some degree 
than that of the atmosphere. Local conditions, such as source of supply, 
length and character of pipe run, and use and permanency of the plant, 
make the selection of pressure difference one of good engineering judgment 
rather than the application of any fixed rule. The proper basis for propor- 
tioning the supply system is dealt with in Chapter 11. 

The primary function of return mains is the removal and disposal of 
the products of condensation. These mains should provide gravity flow 
wherever possible. Pressure difference should be used to stimulate flow only 
where gravity alone is not practical. 

The products to be removed consist of water, air, vapor, gases from 
impurities, and last, but not to be overlooked, dirt. 

The last consists of initial impurities such as core-sand, gravel, chips, 
mill scale, grease, etc., left in the heating system when erected, together 
with rust particles and scale from impure feed water. Were it not for the 

1-4 



dirt which collects and the uncertainty as to its volume, return mains 
might be made much smaller. 

Formulae and tables of capacities of straight, smooth pipes laid on even 
grades for return of condensation, and tables of accepted capacities com- 
pensating for uncertainties of grade and dirt are given in Chapter 12. 

The hot, distilled water should be returned to the boiler wherever pos- 
sible. The saving due to the heat content of this water and its freedom 
from scale-forming and other impurities, warrants considerable initial out- 
lay in return apparatus. 

No specific type of return apparatus will best fit all conditions. The 
simple, low-pressure heating boiler may have its water line so located that 
the water of condensation will flow back into the boiler by gravity against 
the highest steam pressure carried. Between such a boiler and the modern 
high-pressure central generating plant, where part of the exliaust steam is 
used as a by-product for heating purposes in an extended group of build- 
ings, there is a wide range of conditions. The selection of the best combi- 
nation of return apparatus for the individual plant is, therefore, dependent 
upon comprehensive, practical experience. 

Some of the possible combinations of return apparatus are described 
and shown in typical diagrams in Chapter 14, and basic rules are given for 
estimating proper sized apparatus. However, it is manifest that discussion 
in this volume cannot cover all requirements, and in this, as in the selection 
of all apparatus for special conditions, it is recommended that specific 
engineering advice be obtained from the Home Office of Warren Webster 
& Company or its nearest Branch Office, before a selection is made. 



1—5* 



CHAPTER II 
Basic Data Reqviired for the Design of a Steam Heating System 

INTELLIGENT design of any heating system in either new or existing 
buildings requires that certain basic data shall be available. For exist- 
ing buildings the present use of which will continue, it is usually possible 
to obtain quite definite data to work upon. If only plans are available, 
much of the necessary information must be based upon assumptions of 
probable conditions. 

In any event, good judgment, preferably founded upon ripe experience, 
must play its equal part with scientific knowledge in the final application 
of the data obtained. 

Topography: The design of an efficient heating system especially 
where a group of buildings is being considered, requires that a careful study 
be made of the grade levels of the different buildings, each one to the other, 
so that, if possible, the condensation from the heating surfaces may flow 
by gravity to a central point from which it may be returned to the source 
of steam supply. 

In cases where the conditions will not allow of the gravity flow of 
condensate to a central point, special methods for -lifting the condensate 
to a higher level are necessary as described hereafter. 

Location and Character of Source of Heat: It follows from the 
above that wherevei: possible the source of steam supply should be located 
at a lower level than that of the buildings to be heated. 

In a plant consisting of a group of buildings there is usually a power 
generating plant, the by-product from which, in the form of exhaust steam, 
should be utilized to the fullest extent in the heating of the buildings. The 
economies incident to the use of this exhaust steam as a by-product 
frequently determine the adoption of an isolated power generating plant 
rather than the purchase of power from outside sources and the installation 
of a boiler plant for heating purposes only. 

Exposure and Protective Conditions: By exposure is meant the 
relation of the outside surfaces of the building or buildings to the prevailing 
cold winds of winter, which by their pressure cause infiltration of excess 
quantities of cold air and the rapid removal of heat from the outside surfaces 
of the structure. To offset this, a greater amount of radiation must be 
provided on the sides having this exposure, than for the sides more favorably 
located with the protection of surrounding buildings or hills. 

Consequently the designer should determine the direction of the pre- 
vailing winter winds, their probable velocities and duration as well as the 
topographic features which may afford protection. 

Outside Temperatures: Although the records of the U. S. Weather 
Bureau (See Figure 2-1) may show an extreme minimum temperature much 
lower than that usually experienced in a given locality, it is not customary 
to estimate heating requirements with that extreme temperature as a basis. 

Generally, the average minimum temperature, obtained from records 

2—1 




s 



g 



o 

l-l 



6D 



2—2 



over a period of years, is the fundamental consideration, or heating surface 
is provided for an estimated minimum outside temperature approximately 
10 degrees above the lowest recorded minimum, unless this extreme tempera- 
ture is likely to prevail throughout long periods. 

It is possible to operate either the Webster Modulation System or the 
Webster Vacuum System with a slight increase in steam pressure which 
results in an increased rate of heat emission from the radiating surfaces. 
This flexibility may be used to advantage during short periods of unusually 
cold weather. 

Floor Plans, Elevations and Cross Sections : To properly design 
the heating system for a building or buildings, it is necessary that complete 
floor plans and sufficient elevations and cross-sections, showing the details of 
construction, materials, etc., shall be available to assure an accurate calcu- 
lation of the heating requirements. 

In designing heating systems for existing buildings, accurate data may 
be obtained by survey, but with designs of new buildings it is often necessary 
to make certain assumptions which may or may not he justified when the 
construction is complete. A frequent element of error lies in deviations 
from the architect's original plans without proper consideration for their 
effect upon the heating system. 

These possible discrepancies in construction and deviation in design 
from original plans make it quite necessary for the designer of the heating 
system to place himself on record as to the basic factors of his calculation. 

Inside Temperature Requirements: The temperature which it is 
desired to maintain and the lowest degree to which the temperature will be 
allowed to fall, are usually governed by the use which will be made of the 
enclosure. 

Inside temperatures are usually determined at the breathing line and 
not closer than five feet from the most exposed wall. 

The important considerations for decision lie in the following questions: 
Is the heat to be maintained continuously 2'i hours per day or for stated 

portions of the total Vi hours? 

If intermittent heating, how long a time may be allowed to raise the 

room temperature to the required maintained temperature? 

Through how long a period will heat be shut off and hoiv low may 

the room temperature become during this closed down period? 

The following table indicates the usual range in maintained tempera- 
tures desired for various classes of occupancy, but it should be kept in mind 
that temperature is largely a matter of individual preference so that such a 
table can only be considered as a guide in the final selection. 

Table 2-1. Temperature for Various Rooms in Degrees Fahrenheit 

Bath rooms 75 to 85 

Churches 60 to 70 

Entrance halls to public buildings 50 to 60 

Factories 60 to 70 

Foundries 50 to 60 

Gymnasiums 60 to 65 

2—3 



Homes for aged 80 

Hospitals 72 to 75 

Lecture halls 60 to 70 

Living rooms 68 to 72 

Machine shops 60 to 70 

Offices 68 to 72 

Operating room 70 to 90 

Paint shop 80 to 90 

Prisons — Day confinement 60 to 65 

Prisons — Night confinement ". 50 to 55 

Public buildings 68 to 72 

Schools 70 

Shops (stores) 50 to 65 

Swimming halls 70 to 75 

Vestibules for stores and office buildings 70 to 80 

The relative humidity of the atmosphere which is hkely to exist in any 
room or building has a bearing upon the desirable inside temperature. 

For a living apartment, a normal temperature of 70 deg. falir. and rela- 
tive humidity of 50 per cent (about 4 grains of water vapor per cubic foot of 
content) is considered by most authorities to be a very satisfactory condition 
of the air. If the temperature is lower than 70 deg., the relative humidity 
should be higher than 50 per cent or if the temperature is higher, the relative 
humidity should be lower if the same effect of comfort to the occupant is to 
result. 

It is usual, however, that the relative humidity is found to be much less 
than 50 per cent in living apartments heated to 70 deg. fahr. and has been 
observed to be as low as 28 per cent. With very low relative humidity the 
effect upon the occupant is a feeling of chilliness even though the temperature 
may be increased to 78 or 80 deg. fahr. This cooling effect is due to the 
rapid evaporation of moisture from the occupant's skin which is brought 
about by the low vapor pressure of the atmosphere. Conversely, where 
extremely high relative humidity exists, a temperature of 70 deg. fahr. 
might feel oppresively hot to the occupant. 

Contents and Use of Enclosure : A very important consideration 
for the designer is that of the materials and machinery within the enclosiu'e, 
and their capacities for absorbing heat. This has an important bearing 
upon the permissible time limit for warming up. 

Large quantities of material or machinery having a high heat content 
will prolong the time for warming and will have an opposite effect of re- 
tarding the loss of temperature when the heat supply is cut off. 

For consideration of this factor, the designer should have details of the 
weight and substance of each of the various items of machinery and materials. 
With this data and a table of specific heats of substances such as on page 000, 
the total heat contents or heat absorbing capacities which influence the warm- 
ing up period can be determined. 

Likewise, the designer should determine the total heat given off by the 
operation of the machinery, motors, lights, etc., although this is not of so 
much importance in buildings where the temperature requirements are those 
to be maintained during periods when machinery, etc., are not in operation. 

2—4 



In schools, theaters, auditoriums, churches, etc., where large numbers 
of persons may gather, it is necessary to allow for the heat given off by the 
human bodies if overheating is to be prevented. In such cases, ventilation 
is usually required to remove the bodily heat with its excessive humidity. 

In manufacturing plants, portions of buildings often require unusual 
quantities of heat to warm the large amounts of air which replace that drawn 
from the rooms through exhausting fans on grinders, dryers, and similar 
apparatus. This condition requires a careful investigation of the factors 
involved in the unusual rate of air change. 

Character and Location of Heating Surfaces: The selection of 
the radiation from a choice of direct, indirect, direct-indirect, or blast type 
depends largely upon the use for which the enclosure is intended, the ven- 
tilation requirements, the local building laws, school and labor codes, and 
other general considerations. (See Chapter 6.) 

Whether pipe coils, cast-iron wall radiation or the usual cast-iron 
radiators are to be used for direct heating is usually a question of avail- 
abihty of materials, cost of installation and the esthetic effect required. 

The selection of the type and location of the different radiating units 
may best be determined by a study of the plans and elevations of the build- 
ing to be heated. 

Location of Supply and Return Lines : In installations of the type 
of hotels, hospitals, office buildings or other public buildings with finished or 
decorated walls it is customary to conceal the steam and return risers, and their 
run-outs to radiators, in the wall and floor construction. In factory instal- 
lations and other less expensive types of construction these lines are exposed 
and in many instances they are used as prime radiating surfaces. 

In cases where the outlets from the risers are taken below the level of 
entrance to the radiators it is essential that the run-outs shall be so graded 
that the condensation will flow back by gravity into the risers regardless of 
the maximum velocity of steam which may flow in the opposite direction. 
It is therefore of prime importance that the maximum velocity shall be kept 
well below that at which the condensation will be swept along with the steam. 
This important feature of design is discussed in further detail in Chapter 12. 

A down-feed system of supply is preferable wherever building conditions 
will permit since the condensation will then flow in the same direction and 
will be assisted by the flow of steam as well as by gravity. This permits the 
use of smaller supply risers and run-outs due to the higher velocities of 
steam flow which are permissible. 

Return run-outs, risers and mains must grade in the direction of flow of 
condensation to some low point or points from which the condensation will 
be returned to the source of steam supply or other point of disposal. 



2—5=" 



CHAPTER III 
Heat Transmission 

THE same principle of flow of heat from a higher to a lower tem- 
perature which makes steam heating effective also functions in the 

transmission of heat tlirough materials of construction to make 
such heating necessary. 

Heat seeks equilibrium, and consequently flows from a higher to a 
lower temperature with greater or less rapidity, depending upon the dif- 
ference in temperature and the character and thickness of the material 
tlirough which it flows. 

For the purpose of estimating the heat losses from enclosures, numerous 
tests and deductions from practice have been made to determine the rate 
of heat flow or transmission tlu-ough the various types and materials of 
surfaces used for enclosing space. So many variables enter this problem 
that it is impossible to predict the heat flow exactly unless all of the pecul- 
iarities of any case under consideration have been previously determined. 

Tables of Heat Transmission, therefore, attempt to provide for average 
conditions of construction of the enclosing substances. Due regard is given 
to the facility with which heat is absorbed and removed from the surfaces 
of the enclosing substances, and to the heat which is transmitted through 
them due to the difference between the temperatures existing at their sur- 
faces which may be termed "heat head." 

This heat head has been considered in many formulae as a constant 
increase per degree of temperature difference. As the result of tests with 
the same substance under various temperature differences this deduction 
has been proved to be incorrect. Higher temperature differences cause a 
greater heat flow per degree difference than lower temperature differences. 



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.10 .20 .30 .40 .50 .60 .70 .80 .90 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 
FACTORS FOR TEMPERATURE DIFFERENCE OTHER THAN 70° (TO BE APPLIED AS A PERCENTAGE OF 
FACTORS FOR STANDARD.) 

Fig. 3-1. Factors for temperature differences other than 70 deg. 



3.00 



3—1 



Table 3-1. Factors for Temperature Differences other than 70 degrees Fahrenheit 

Where temperature difference is 40° 50° 60° 70° 80° 90° 100° 110° 120° 130° 140° 150° 160° 
Multiply Transmission Losses 
for 70 deg. difference by 50 .66 .82 1.00 1.19 1.39 1.59 1.80 2.00 2.25 2.50 2.75 3.00 



The probable variation in heat flow under various conditions of heat 
head is shown in Table 3-1. The rate of flow for any difference between 
inside and outside temperatures other than 70 deg. is expressed as a per- 
centage of that which will flow at 70 deg. difi^erence. (See Figure 3-1, 
which is a curve constructed from the values in Table 3-1.) 

The discussion of Rates of Heat Transmission in this book recognizes 
the following fundamental conditions: 

(1) The maintained inside temperature is that normally existing at 
the breathing line (5 feet above the floor) and about 5 feet from a wall. 
The breathing line is more often mentioned hereafter as the datum line. 

(2) The basic rate of transmission for any substance is the number of 
B.t.u. which will be transmitted in an hour through each square foot of sur- 
face of that substance when the outside temperature is zero and the main- 
tained inside temperature is 70 deg. fahr. 




Fig. 3-2. Illustrating the examples of heat stratification on page 00. 



3—2 



(3) From the above it will be evident that the basic rate is that which is 
transmitted at the datum line. 

(4) Tests in structiu-es where the air is not agitated or mixed by moving 
fans, belts, pulleys, etc., indicate that an increase of temperature of about 
1 deg. for each foot from the datum hue may be expected up to the point 
where heat is lost by transmission through the roof or ceiling. 

(5) This point where heat is lost through a roof or ceiling is assumed 
to be 5 feet below the surface of same. 

(6) Because of this stratification of heat, it is necessary, in the case of 
high structures, to figure upon an increase in rate of transmission due to 
the greater heat head caused by the higher average inside temperature. 

The application of this so-called stratification, or height factor, differs 
for roofs, for windows, and for such vertical surfaces as walls, doors, parti-" 
tions, etc. 

For instance, if the average height or center of a window is 10 feet above 
the floor line, as in Figure 3-2, the temperature Ti which might be expected 
at that point is 70 deg. plus 1 deg. for each foot of height of the center 
of the window above the 5-foot datum line, or 75 deg. 

Due to the higher temperature difference of zero to 75 deg. instead of 
the standard to 70 deg. and the consequent increase of heat head, the trans- 
mission losses must be increased by a factor or per cent of the loss exist- 
ing at the 5-foot line where to 70 deg. is assumed to exist. 

This factor F is obtained from Figure 3-1 and for 75 deg. difference the 
transmission losses are found to be 109 per cent of the normal. 

For any other window the inside temperature Ti assumed to exist at 
the average height is 

Ti = ('^^ -h Di — 5 ) deg. + 70 deg. or 

Ti = ^ + Di + 65 

where Di is the number of feet of height above floor of the lower edge of 
window opening and Hi is the number of feet of height between upper and 
lower edges of window opening. In every case the factor F to be appHed 
to normal transmission loss is obtained from Figure 3-1. 

Because of the transmission of heat tlirough roof construction, it is 
usual to consider in connection with roof factors that the inside temperature 
does not increase due to stratification beyond 5 feet below the under side of 
the roof. Therefore, the factor for stratification assumes the existence of 
two limits, one 5 feet above the floor and the other 5 feet below the roof. 

For instance, in a building having a sloping roof which has an average 
height above floor of 23 feet, as in Figure 3-2, the average temperature 
under the roof is assumed to be that existing 5 feet below the roof or 18 feet 
above the floor. The temperature at that point is assumed to be 70 + 18-5 
or 83 deg. 

The temperature Ti for the factor to be used for a roof of any other 
distance above the floor is Ti = (H2 — 10) deg. + 70 deg. or H2 + 60 
where H2 is the number of feet of average height of the roof above the floor. 

a— 3 



With the temperature Ti known, the factor F to be apphed for heat 
head may be obtained from Figure 3-1. 

For convenience, the revised heat transmission rates for different heights 
of roofs have been shown in the following tables. 

Heat losses tlirough monitors must be specially considered. In such 
cases it is usual to install heating surfaces within the monitor construction, 
and for that reason the entire monitor construction should be considered 
as an individual unit of enclosure with an imaginary floor across the space 
between its lower edges. 

However, the factors for stratification for figuring heat losses from moni- 
tors should disregard the 5-foot roof datum line; that is, it is assumed that 
the temperature at this imaginary floor line is approximately 70 deg. 

For walls, doors, partitions, or any other vertical surfaces the lower 
edge of which is at floor level, the method of obtaining the factor for strati- 
fication is the same as for windows, above described, except that the formula 
for obtaining the temperature (Ti) at the point of average height is 



Ti = (^^-5)deg. + 70deg. 



where H3 is the number of feet of height above floor of the upper edge of the 
surface. 

In the cases where consideration must be given to the transmission of 
heat tlxrough floors, such as floors above cellars or other cold spaces, and floors 
laid upon the ground, it is unnecessary to provide factors for stratification, 
since the transmission rate at the established difference in temperature be- 
tween underside of floor and datum line covers this loss with a margin of 
safety. 

It will be understood that the foregoing factors have all been adjusted 
for the basic temperature difference between zero outside and 70 deg. main- 
tained inside. 

If the outside temperature for which any particular enclosure is figured 
is different from zero, or if the temperature to be maintained at the breath- 
ing line is more or less than 70 deg., or if both inside and outside tem- 
peratures are different from basic, the rates of transmission should again be 
adjusted for the new difference in temperature. 

This new factor is obtained from Table 3-1 or Figure 3-1, and is applied 
to the total of all transmission losses through the structure which have 
previously been calculated for the standard 70 deg. difference. 



3—4 



Rates of Heat Transmission in B. t. u. per hour per sq. ft. of 

Surface for Temperature Difference, deg. to 70 deg. Fahr. 

Table 3-2. Walls, Clapboard 



CONSTRUCTION 



TOTAL HEIGHT OF WALL 
10 Ft. 15 Ft. 20 Ft. 25 Ft. 35 Ft. 45 Ft. 55 Ft. 

F = 1.00 F = 1.04 F = 1.09 F = l,14 F = 1.23 F = 1.33 F=1.43 



Clapboard on studs — bare 

Clapboard on studs — papered inside 

Clapboard on studs — with lath and plaster 
Clapboard on studs — paper with lath and 

plaster 

Clapboard on studs — with 1-in. sheathing 

bare 

Clapboard on studs — with 1-in. sheathing 

papered 

Clapboard on studs — with 1-in. sheathing 

lath and plaster 

Clapboard on studs — with 1-in. sheathing 

papered, lath and plaster 

Clapboard on studs — with 1-in. sheathing 

wood insulation, papered 

Clapboard on studs — with brick fill — bare. 
Clapboard on studs — with brick fill — 

papered 

Clapboard on studs — with brick fill — lath 

and plaster _ 

Clapboard on studs — with brick fill — 

papered, lath and plaster 

Clapboard on studs — saw dust fill, inside 

sheathing, lath and plaster 

Clapboard on studs — saw dust fill, inside 

sheathing, papered, lath and plaster .... 
Clapboard on studs — sheathing, back plas- 
ter, lath and plaster 



50 
45 
35 


52 
47 
36 


55 
49 
38 


57 
51 
40 


62 
55 
43 


67 
60 

47 


72 
64 
50 


30 


31 


33 


34 


37 


40 


43 


40 


42 


44 


46 


49 


53 


57 


35 


36 


38 


40 


43 


47 


50 


32 


33 


35 


37 


39 


43 


46 


25 


26 


27 


29 


31 


33 


36 


35 
28 


36 
29 


38 
31 


40 
32 


44 
34 


47 
37 


50 
40 


25 


26 


27 


29 


31 


33 


36 


22 


23 


24 


25 


27 


29 


31 


20 


21 


22 


23 


25 


27 


29 


15 


16 


16 


17 


18 


20 


21 


10 


10 


11 


11 


12 


13 


14 


25 


26 


27 


29 


31 


33 


36 



Table 3-3. Walls, Stucco on Studs 



CONSTRUCTION 



TOTAL HEIGHT OF WALL 
10 Ft. 15 Ft. 20 Ft. 25 Ft. 35 Ft. 45 Ft. 

F = 1.00 F = 1.04 F = 1.09 F = 1.14 F = 1.23 F = 1.33 



55 Ft. 
F = 1.43 






Plaster With wood lath and plaster 
^ on the inside 



40 



42 



44 



46 



49 



53 



57 



n 



Plaster With metal lath and plaster 
^ on the inside 



45 



47 



49 



51 



55 



60 



64 



Table 3-4. WsJls, Corrugated Iron 



CONSTRUCTION 



TOTAL HEIGHT OF WALL 
10 Ft. 15 Ft. 20 Ft. 25 Ft. 35 Ft. 

F=1.00 F = 1.04 F = 1.09 F=1.14 F = 1.23 



45 Ft. 
F = 1.33 



55 Ft. 
F = 1.43 



r ( Lap 



Plain loose construction. 



125 



130 



136 



143 



154 



166 



179 



Coi._^ Lap 

(VnoAir Plain tight construction. 



90 



94 



98 



103 



111 



120 



129 



Cor—: 
Iron 



_Woo4 Sheathed, tongued and 

grooved 45 



47 



49 



51 



55 



60 



64 



3—5 



Rates of Heat Transmission (Continued) 
Table 3-5. Walls, Brick 



IN INCHES 


10 Ft. 


15 Ft. 


20 Ft. 


25 Ft. 


35 Ft. 


45 Ft. 


55 Ft. 


T 


F = 1.00 


F = 1.04 


F=1.0<> 


F=1.14 


F = 1.23 


F = 1.33 


F = 1.43 



Plain 



4 


.•50 


52 


55 


57 


62 


67 


72 


8 


30 


31 


33 


34 


37 


40 


43 


12 


■22 


23 


24 


25 


27 


29 


31 


16 


18 


19 


20 


21 


22 


24 


26 


20 


16 


17 


17 


18 


20 


21 


23 


24 


14 


15 


15 


16 


17 


19 


20 


28 


12 


13 


13 


14 


15 


16 


17 


32 


10 


10 


11 


11 


12 


13 


14 


36 


8 


8 


9 


9 


10 


11 


11 



Plastered 



4 


48 


50 


52 


55 


59 


64 


69 


8 


28 


29 


31 


32 


34 


37 


40 


12 


20 


21 


22 


23 


25 


26 


29 


16 


15 


16 


16 


17 


18 


20 


21 


20 


14 


15 


15 


16 


17 


19 


20 


24 


12 


13 


13 


14 


15 


16 


17 


28 


11 


12 


12 


13 


14 


15 


16 


32 


10 


10 


11 


11 


12 


13 


14 


36 


8 


8 


9 


9 


10 


11 


11 



Furred and Plastered 




4 


32 


33 


35 


37 


39 


43 


46 


8 


20 


21 


22 


23 


25 


27 


29 


12 


15 


16 


16 


17 


18 


20 


21 


16 


12 


13 


13 


14 


15 


16 


17 


20 


11 


12 


12 


13 


14 


15 


16 


24 


9 


9 


10 


10 


11 


12 


13 


28 


8 


8 


9 


9 


10 


11 


11 


32 


7 


7 


8 


8 


9 


9 


10 


36 


6 


6 


7 


7 


7 


8 


9 



Table 3-6. WaUs, HoUow Tile 



THICKNESS 
IN INCHES 10 Ft. 
T F = 1.00 



15 Ft. 
F = 1.04 



TOTAL HEIGHT OF WALL 



20 Ft. 
F = 1.09 



25 Ft. 
F = 1.14 



35 Ft. 
F = 1.23 



45 Ft. 
F=1.33 



55 Ft. 
F=1.43 



Plain 



4 


45 


47 


49 


51 


55 


60 


64 


6 


40 


42 


44 


46 


49 


53 


57 


8 


28 


29 


31 


32 


34 


37 


40 


10 


24 


25 


26 


27 


30 


32 


34 


12 


18 


19 


20 


21 


22 


24 


26 



3—6 



* (Table 3-6 continued on next page) 



Rates of Heat Transmission (Continued) 

Table 3-6. WaUs, HoUow Trie {Continued) 



'■"HICKNESS 

IN INCHES 10 Ft 

"^ F=i.ob 



TOTAL HEIGHT OF WALL 



15 Ft. 
F = 1.04 



20 Ft. 
F=1.09 



25 Ft. 
F = 1.14 



35 Ft. 
F=1.23 



45 Ft. 
F = 1.33 



Plastered ort One Side 



55 Ft. 

F = 1.43 




4 

6 

8 

10 

12 



40 
3.5 



20 
16 



42 
36 
26 
21 
17 



44 
38 

27 
22 
17 



46 
40 
29 
23 
18 



49 

43 
31 
25 
20 



53 

47 
33 
27 
21 



57 
50 
36 
29 
23 











Stucco, 


FUBRED 


AND Plastered 






^T-^ 


















•r 


"',"7 


4 


30 


31 


33 


34 


37 


40 


43 


1 1 1 


:-k 


6 


28 


29 


31 


32 


35 


37 


40 


!□ 


!■) 


8 


20 


21 


22 


23 


25 


27 


29 


!"■. 


10 


16 


17 


17 


18 


20 


21 


23 


u 


I-;; 


12 


14 


15 


15 


16 


17 


19 


20 


IQ- 


iii 



















Table 3-7. Walls, Hollow Tile faced with Brick 



THICKNESS 
IN INCHES 



TOTAL HEIGHT OF WALL 



10 Ft. 
F = 1.00 



15 Ft. 
F = 1.04 



20 Ft. 
F = 1.09 



25 Ft. 
F=1.14 



35 Ft. 
F = 1.23 



45 Ft. 55 Ft. 

F = 1.33 F=1.43 



Plain 



<*» 


u 

D 
D 
D 



12 
16 



26 
20 



15 
12 



27 

25 

16 
13 



28 



16 
13 



30 
23 



17 
14 



32 
25 



18 
15 



35 

27 

20 
16 



37 
29 



21 

17 



Plastered 




4 


4 


24 


25 


26 


27 


30 


32 


34 


4 


8 


18 


19 


20 


21 


79 


24 


26 


4 


12 


12 


13 


13 


14 


15 


16 


17 


4 


16 


10 


10 


11 


11 


12 


13 


14 



Furred and Plastered 




12 
16 



18 
15 



10 
8 



19 
16 
10 



20 
16 
11 



21 
17 



11 
9 



18 



12 
10 



24 
20 



13 
11 



26 
21 



14 
11 



3—7 



Rates of Heat Transmission (Continued) 
Table 3-8. Walls, Concrete faced with Brick 4 inches thick 



THICKNESS 
IN INCHES 



10 Ft. 
F = 1.00 



15 Ft. 
F = 1.04 



TOTAL HEIGHT OF WALL 



20 Ft. 
F = 1.09 



25 Ft. 
F = 1.14 



35 Ft. 
F = 1.23 



45 Ft. 
F = 1.33 



55 Ft. 
F=1.43 



Plain 




12 
16 



35 
28 
22 
18 



36 
29 
23 
19 



38 
31 
24 
20 



40 
32 
25 
21 



43 
34 

27 
22 



47 
37 
29 
24 



50 
40 
31 
26 



Plastered 




12 
16 



32 

25 
20 
16 



33 
26 
21 
17 



35 



22 
17 



37 
29 
23 
18 



38 
31 
25 
20 



43 
33 

27 
21 



46 
36 
29 
23 



Furred and Plastered 




4 

« 

12 

16 



24 
20 
15 
12 



25 
21 
16 
13 



26 



16 
13 



27 
23 
17 
14 



30 
25 
18 
15 



32 

27 
20 
16 



34 
29 
21 
17 



Table 3-9. Walls, Stone faced with Concrete 4 inches thick 





TJ ICKNESS 
IN INCHES 

C T 


10 Ft. 
F = 1.00 


15 Ft. 
F = 1.04 


TOTAL HEIGHT 

20 Ft. 25 Ft. 
F=1.09 F = 1.14 


OF WALL 

35 Ft. 
F = 1.23 


45 Ft. 
F = 1.33 


55 Ft. 
F = 1.43 


Plain 




<s> 


^^ 


4 4 

4 

4 12 

4 16 


50 
40 
35 

27 


52 

42 
36 
28 


55 57 
44 46 
38 40 
29 31 


62 
49 
43 
33 


67 

53 

47 
36 






1 

i 




72 
57 
50 
39 









3—8 



(Table 3-9 continued on next page) 



Rates of Heat Transmission (Continued) 

Table 3-9- Walls, Stone faced with Concrete 4 inches thick (Continued) 



THICKNESS 
IN INCHES 



10 Ft. 
F=1.00 



IS Ft. 
F=1.04 



TOTAL HEIGHT OF WALL 



20 Ft. 
F = 1.09 



25 Ft. 
F = 1.14 



35 Ft. 
F=1.23 



45 Ft. 
F=1.33 



55 Ft. 
F = 1.43 



Plastered 





«s* 


«» 






















i 




1 4 


4 


45 


47 


49 


51 


55 


60 


64 




m 




i: 4 


8 


36 


37 


39 


41 


44 


48 


52 




h 




i 4 


12 


32 


33 


35 


37 


39 


43 


46 




!^^ 




Si 4 


16 


24 


25 


26 


27 


30 


32 


34 




S^ 




:• 




















iii& 




1 































FUBRED AND PLASTERED 












<€-^ 


1 4 

:^ 4 

'i: 4 


4 

8 

12 

16 


33 

27 
23 
18 


34 36 38 
28 29 31 
24 25 26 
19 20 21 


41 
33 
28 

22 


44 
36 
31 
24 


48 
39 
33 
26 











Table 3-10. Walls, Porous Stone or Porous Concrete 



THICKNESS 
IN INCHES 



10 Ft. 
F=1.00 



15 Ft. 
F = 1.04 



TOTAL HEIGHT OF WALL 



20 Ft. 
F = 1.09 



25 Ft. 
F=1.14 



35 Ft. 
F = 1.23 



45 Ft. 
F = 1.33 



55 Ft. 
F = 1.43 



Mm 



Plain 



4 


75 


78 


82 


86 


92 


100 


107 


6 


0.3 


66 


71 


74 


80 


87 


93 


8 


55 


57 


60 


63 


68 


73 


79 


10 


50 


52 


55 


57 


62 


67 


72 


12 


45 


47 


49 


51 


55 


60 


64 


16 


38 


40 


42 


43 


47 


51 


54 


20 


33 


34 


36 


38 


41 


44 


47 


24 


27 


28 


29 


31 


33 


36 


39 




Plastered 



4 


67 


70 


73 


76 


83 


89 


96 


6 


58 


60 


63 


66 


71 


77 


83 


8 


49 


51 


53 


56 


60 


65 


70 


10 


45 


47 


49 


51 


55 


60 


64 


12 


41 


43 


45 


47 


50 


55 


59 


16 


34 


35 


37 


39 


42 


45 


49 


20 


29 


30 


32 


33 


36 


39 


42 


24 


24 


25 


26 


27 


30 


32 


34 




■A-'J>.C<. 

■..^■' ■'£>•■.'.• 



Stucco, Fubhed and Plastered 



4 


50 


52 


55 


57 


62 


67 


72 


6 


43 


45 


47 


49 


53 


57 


62 


8 


37 


39 


40 


42 


46 


49 


53 


10 


33 


34 


36 


38 


41 


44 


47 


12 


30 


31 


33 


34 


37 


40 


43 


16 


25 


26 


27 


29 


31 


33 


36 


20 


22 


23 


24 


25 


27 


29 


31 


24 


18 


19 


20 


21 


22 


24 


26 



3—9 



Rates of Heat Transxaission (Continued) 
Table 3-11. Walls, Hard Stone or Concrete 



THICKNESS 
IN INCHES 



TOTAL HEIGHT OF WALL 



10 Ft. 
F=1.00 



IS Ft. 
F=1.04 



20 Ft. 
F = 1.09 



2SFt. 
F = 1.14 



35 Ft. 
F = 1.23 



45 Ft. 
F=1.33 



55 Ft. 
F = 1.43 



Plain 



4 


70 


73 


76 


80 


86 


93 


10 


6 


60 


62 


65 


68 


74 


80 


86 


8 


50 


52 


55 


57 


62 


67 


72 


10 


45 


47 


49 


51 


55 


60 


64 


12 


40 


42 


44 


46 


49 


50 


57 


16 


35 


36 


38 


40 


43 


47 


50 


20 


27 


28 


29 


31 


33 


36 


39 


24 


20 


21 


22 


23 


25 


27 


29 



Plastered 




4 


63 


66 


69 


72 


78 


84 


90 


6 


54 


56 


59 


62 


67 


72 


77 


8 


45 


47 


49 


51 


55 


60 


64 


10 


41 


43 


45 


47 


51 


55 


59 


12 


36 


37 


39 


41 


44 


48 


52 


16 


32 


33 


35 


37 


40 


43 


46 


20 


24 


25 


26 


27 


30 


32 


34 


24 


18 


19 


20 


21 


22 


24 


26 



Stucco, Furred and Plastered 




4 


47 


49 


51 


54 


58 


63 


67 


6 


40 


42 


44 


46 


49 


53 


57 


8 


33 


34 


36 


38 


41 


44 


47 


10 


30 


31 


33 


34 


37 


40 


43 


12 


27 


28 


29 


31 


33 


36 


39 


16 


23 


24 


25 


26 


28 


31 


33 


20 


18 


19 


20 


21 


22 


24 


26 


24 


13 


14 


14 


15 


16 


17 


19 



Table 3-12. Roof Glass and Skylights 

The surface to be considered is the total surface of glass and frame. 



CONSTRUCTION 


BASIC 

RATE 
F = LOO 


AVERAGE HEIGHT 

25 Ft. 30 Ft. 
F = L27 F=1.38 


OF ROOF ABOVE 

35 Ft. 45 Ft. 
F = 1.48 F=L70 


FLOOR 

55 Ft. 
F = 1.90 


W00d^ , , 

m^r — t^ 


Wood frame, single glazed . . . 


75 


95 


104 


111 


128 


143 


Wood-) ^ Glass 

fTTTT f 7777% 


Wood frame, double glazed. . . 


42 


53 


58 


62 


72 


80 


r///k — 7f t2222 

Glass^ 


Glass-/ 


Iron sash, single glazed 


. 90 


114 


124 


133 


153 


171 


Iron--) xGlass 


Iron sash, double glazed 


60 


76 


83 


89 


102 


114 


Glass -^ 



3—10 



Rates of Heat Transmission (Continued) 
Table 3-13. Windows 



CONSTRUCTION 



Basic 

(or Rate) 

Factor 



Wood 



Wood Frame 
Single Glazed 



75 



'^ 



^ Gl ass 



Wood Frame 
Double Glazed 



42 



The factors in this table are for trans- 
mission rates at the datum Une 5 feet from 
floor and a temperature of 70 deg. Fahr. 
The temperature Ti at the centre of a 
window of any height above the floor will be 



Solid M etal 
Glass^ 



Metal Frame 
Single Glazed 



90 



T: = (|>+D,-5)' 



+70° 



Hollow Metal 



■ 4^3 



Metal Frame 
Single Glazed 



80 



Solid M etal 



7^ 



Metal Frame 
Double Glazed 



60 



Where Hi is the number of feet of height 
of the upper edge of window 
opening above lower edge. 
Di is the number of feet of height 
of the lower edge of window 
opening above the floor. 

With Ti established, the factor for cor- 
recting the tabular values will be deter- 
mined from Fig. 3-1. Apply this corrected 
factor to the entire area of window opening. 

Monitors must be considered as separate problems as if they are structures of themselves with 
theoretical floors at the level of the base of the monitor. Their transmission losses and the sizing and placing 
of radiating surfaces should be figured accordingly. The factor should disregard the usual 5-foot datum 
line. That is, assume that the temperature at this imaguiary floor line is 70 deg. Fahr. 



/: 



^ 



Gl ass 



Metal Frame 
Double Glazed 



44 



Table 3-14. Roof Construction 



BASIC AVERAGE HEIGHT OF ROOF ABOVE FLOOR 



CONSTRUCTION 



RATE 
F=1.00 



25 Ft. 
F=1.27 



30 Ft. 
F = 1.38 



35 Ft. 
F = 1.48 



45 Ft. 
F = 1.70 



55 Ft. 
F = 1.90 



Tile on strips 85 

Tile on sheathing 45 

Slate on strips 85 

Slate on sheathing and paper 35 

Corrugated iron on strips 125 

Corrugated iron on sheathing 45 

Tin on strips 110 

Tin on sheathing 40 

Tin on sheathing with paper 30 

Shingles on strips 60 

Shingles on sheathing 30 

Shingles on strips over tar paper and tight boards. . 15 

Cinder composition 2-in. paper, tar and gravel 25 

Concrete composition 2-in. paper, tar and gravel. . . 50 

Concrete composition 3-in. paper, tar and gravel. . . 45 

Concrete composition 4-in. paper, tar and gravel. . . 45 

Hollow tile 4-in. paper, tar and gravel 20 

HoUow tile 6-in. paper, tar and gravel 18 

MetropoUtan 3-in. paper, tar and gravel 20 

Metropolitan 4-in. paper, tar and gravel 15 

1-in. wood with 5 to 8-ply paper and gravel 20 

IJ^-in. wood with 5 to 8-ply paper and gravel 18 

2-in. wood with 5 to 8-ply paper and gravel 15 

2}4-ia. wood with 5 to 8-pIy paper and gravel 12 

2-in. Federal cement tile, paper and tar and gravel . 50 



108 


117 


126 


145 


162 


57 


62 


67 


77 


86 


108 


117 


126 


145 


162 


45 


48 


52 


60 


67 


159 


173 


185 


213 


238 


57 


62 


67 


77 


86 


140 


152 


163 


187 


209 


51 


55 


59 


68 


76 


38 


41 


44 


51 


57 


76 


83 


89 


102 


114 


38 


41 


44 


51 


57 


19 


21 


22 


26 


29 


32 


35 


37 


43 


48 


64 


69 


74 


85 


95 


57 


62 


67 


77 


86 


57 


62 


67 


77 


86 


25 


28 


30 


34 


38 


23 


25 


27 


31 


34 


25 


28 


30 


34 


38 


19 


21 


22 


26 


29 


25 


28 


30 


34 


38 


23 


25 


27 


31 


34 


19 


21 


22 


26 


29 


15 


17 


18 


20 


23 


64 


69 


74 


85 


95 



3—11 



Rates of Heat Transmission (Continued) 
Table 3-15. Floors 



Thickness Basic 
in (or Rate) 

Inches Factor 



Concrete 

Tile or Metal 

Laid on Cinder 
Fill on Ground 
without Air Space 



Note — ^For figuring the opposite heat losses apply the factors 
only to that part of the floor area which lies within 5 feet of the 
outside walls. 

The interior is to be considered for "warming up" only; that is 
the calculation for this part involves the use only of the specific 
heat of the material which is to be multiplied by its weight times 
the difi'erence between initial and final temperature. 



ABOVE COLD SPACE 



DESCRIPTION 



Basic 
Rate 



Wood -> 



Wood -' 
-Joists — 



-r^EI 



Paper 



Mill construction — 3-in. wood and paper plus J^-in. surface. 1.5 



Single wood on Joists 40 



Double wood on Joists. 



30 



>^" Single wood on Joists with lath and plaster. 



30 



.Hoist vtouo * Joist '■M~' Double wood on Joists with lath and plater 20 

"""^Lath and Pla^ipr ' ' . 



lt;|-Joisi "" Wood •" lms\M , Double wood on Joists with insulation and lath and plaster. 10 

'-Insulation '^-- Latll and Plaster 



Woodj^, 



IzJ:- 



nT Double wood on fireproof concrete 10 



^ood v>uuo ^ ^"S^ 



Wood flooring on double wood and fireproof concrete .5 



Concrete.^ 



)fc;gi-o--^!;-^j--- - - -^. ^p -i^.'i^. ^-^^ ^jjjj Concrete Slab, metal reinforced . 

Reinforced uoncreie-^ 



70 



liSE^ESSg^S^^]^a ^,_jj,_ Concrete Slab, metal reinforced . 



60 



p^^^i^'i:^:i-r-:^°:-^iS^<i?fpniJ^ 8-in. Concrete Slab, metal reinforced . 

Reinforced Concrete-^ 



50 



m&S^yS^vmiJ^J^c&ifi^^^ 



Reinforced Concrete- 



■^^ 



10-in. Concrete Slab, metal reinforced. 



45 



Table 3-16. Doors and Wood Partitions 



CONSTRUCTION 



TOTAL HEIGHT OF 
DOOR OR WOOD PARTITION 

10 Ft. 15 Ft. 20 Ft. 25 Ft. 

F=1.00 F = 1.04 F = 1.09 F=1.14 



" to 1 
"to 1 
" to I 
" to 
" to 
" to 3 

12" 



" thick, tongued and grooved. 
]-i" thick, fongued and grooved. 
34" lliick. tongued and grooved. 

" thick, tongued and grooved. 
14" thick, tongued and grooved. 

" thick, tongued and grooved. 



45 


47 


49 


51 


40 


42 


44 


44 


35 


36 


38 


40 


30 


31 


33 


34 


25 


26 


27 


29 


20 


21 


-7 '7 


23 



CHAPTER IV 
Air Infiltration 

WIND blowing against walls causes a leakage of air into the enclosure 
and an outward leakage from the enclosure through the opposite 
sides. Additional leakage is caused by temperature difference within 
and without regardless of wind velocity. These leakages are sometimes 
rtferred to as air change, but in this book are called air infiltration. 

As the air enters and leaves the enclosure at different temperatures, 
sufficient B.t.u. or heat units must be provided to heat this air between the 
two temperatures. Air infiltration therefore becomes one of the important 
factors in the detennination of heat losses in a room or an enclosure. 

Some methods or formulae for determining the heat losses of an en- 
closure, either include the loss due to air infiltration in the heat transmission 
factors or base it upon the cubic contents of the space to be heated. 

Examination of the air infiltration shows that most of the air leaks are 
around the doors, windows and other similar openings. The quantity that 
expresses the heat loss due to this infiltration of cold air should therefore be 
based upon the sum of the openings through which this leakage occurs, 
rather than upon the area of the doors, windows and similar openings of 
the structure. 

Any determination of the quantity of air infiltrated must take into 
consideration the velocity and direction of the wind in relation to the 
openings of the enclosure. Where an enclosure has openings on more than 
one side, the infiltration for all openings must be determined and the 
rad:ation for this loss proportioned and located according to the maximum 
degree of infiltration that may occur on any side. This method will give an 
excess of radiation on the sides where leakage is outward, but there is no 
alternate without having some sides of the room feel cool at some wind 
direction. 

The leakage in narrow monitors and rooms where cold drafts will not 
be objectionable may be considered only on the side where maximum wfnd 
velocities occm". A portion of the heat to care for this infiltration can then 
be applied to the other side. Where the wind strikes the surface at an angle, 
the resultant velocity at right angles to the siu-face must be considered. 
This is equal to the actual velocity times the sine of the angle of incidence. 

Normally, the same maximmn wind velocity should be considered on 
the north and west sides, while on the south and east sides one-half of these 
velocities may be used except where special wind conditions exist. 

A suggested extreme condition for New York and vicinity would be 
20 miles per In*, wind velocity with a temperature of zero. Generally low 
wind velocities prevail at extreme low temperatures. 

The many variables make reference to experiment easier than attempt- 
ing to deternune theoretically the perimeter air infiltration of windows, doors 
and similar openings. Little dependable experimental data is available at 
present, but this must be used as a basis until better is to be had. 

Experiments on air infiltration of windows have been made by using a 

4—1 



fan to direct wind velocities against a test window set in the side of a tight 
enclosure and having an opening for Pitot tube readings on the opposite 
side. Further details regarding some of these experiments by Whitten will 
be found in the 1908 Transacti<n? of the American Society of Heating and 
Ventilating Engineers, and others by Voorhees and Me>/er in the 1916 
Transactions. 

Figure 4-1 gives the approximate leakage in cubic feet per minute per 
lineal foot of sash perimeter for a good frame, double-hung locked window, 
with and without metal weather strip. 



70 



60 



5 50 



.£ 30 





1 




/I 






















A 








/ 
























1 






1 






















X 








— 


- 




/ 




















/ 












/ 
















/ 


/ 
















11 














/ 


/ 
















— 


il 














/ 


/ 


















t 












o^ 


/ 




















^/ 










/ 


^ 






























/ 


/ 






























/ 


/ 
































/ 


/ 




























/ 




/ 


/ 


































/ 
































/ 


































1/ 





































01234567H9 
Air Infiltration in Cubic Feet per Minute per Lineal Foot of Aperture 

Fig. 4-1. Air infiltration for wood-sash window. 

Due allowance must be made for loose-fitting sash, metal sash, pivoted 
sash, etc. In windows with steel section freunes properly bedded, only the 
perimeter of that portion which opens need be considered. With standard 
double-hung sash, the meeting rail must be considered with the perimeter. 

The leakage values as read from Figiu-e 4-1 when multiplied by 60 
times 0.087 (density of the air at zero), times 0.24 (specific heat of the air), 
will give the heat units per hour necessary to warm the infiltrated air one 
degree per foot of perimeter. 

4^2 



The following constants will be of value in calculating, as the product 
of the constant for the proper temperature difference and the air infiltration 
in cubic feet per minute gives the B.t.u. per hour required to heat this air 
through the temperature difference selected. 

Example: Assume a double-hung frame window 3 ft. wide by 6 ft. high 
with perimeter of 21 ft., outside temperature 0, inside temperatm^e 70 deg. 
fahr. with wind velocity of 20 miles per hr. Referring to Figure 4-1, the 
leakage per foot of perimeter is found to be 1.6. The conversion factor 
from the table is 87.696. Then 21 X 1.6 X 87.692 = 2946 B.t.u. per hr. 
are required to heat the air infiltration from this window. 



Temperattire Difference Conversion factor 

between inside and outside Cubic ft. per min. 

air in deg. fahr. to B.t.u. per hr. 

1 1.253 

40 50.112 

50 62.640 

60 75.168 

80 100.224 



4-3* 



CHAPTER V 
Method of Calculating Heat Losses 

CHAPTERS 1 and 2 give the general requirements that must be known 
in calculating the heat losses of any structure. Several rules and 
formulae have been devised to determine the amount of heat that 
must be supphed to maintain a room or enclosure at a predetermined 
temperature with a known surrounding temperature. 

Many of these formulae are derived for an average size room and con- 
struction with standard size window openings, etc., and are not flexible 
enough to cover the problems of today. 

If the air within an enclosure is maintained at a temperature higher 
than that surrounding, there must be a natural transfer of heat through 
the enclosing structure to the air of lower temperatures. This transfer may 
be to the air outside, to any adjoining rooms and to air above and below if 
these are at lower temperatiu-e than that in the room. 

To heat the enclosure to and maintain it at a predetermined temper- 
ature, heat must be supplied equivalent to and at the rate at which it is 
lost. The most acciu^ate method of determining this loss as generally agreed, 
is to determine the hourly rate of heat transfer from -the heated enclosure to 
the surrounding air. This loss is usually calculated in British thermal units 
per hour; that is, on the B.t.u. basis. 

The total losses are made up of four principal heat requirements. 

First, is the heat required to weirm to the desired inside temperature the 
air that leaks in through the various openings around the window and door 
perimeters, etc., from the outside. To calculate this loss, the width and 
lineal feet of the openings, and the wind velocity against the side of the. 
enclosure where the openings are located, must be found, and with this data 
the air infiltration determined. The product of the air infiltrated in cubic 
feet per hour, the density of the air, its specific heat and the difference 
between the inside and outside temperatures is the heat required per hour 
for this loss. This subject is further discussed in Chapter 4 on Air Infiltration. 

Second, is the loss by transmission of the heat tlirough the various 
materials of which the enclosure is constructed. To calculate this loss, the 
area and kind of the various materials through which loss occurs, and the 
temperatm'e difference between the air on the two sides of the material 
must be known. 

The product of the area of any material in square feet, the transmission 
coefficient for that material in B.t.u. per hour, and the difference between 
the inside and outside temperatures will give the heat required per hour for 
the loss by transmission through that particular material. The sum of the 
losses so found for all materials of the structure is the total loss of heat from 
the enclosure by transmission. 

A desired maintained interior temperature of 70 deg. fahr. and a mini- 
mum external temperature of zero have been adopted in this book as a 
standard. All transmission coefficients, therefore, are given in B.t.u. per 
hour per square foot of surface for this temperature difference, with correc- 
tion factors for other differences. 

5—1 



A table of these factors for various materials used in building con- 
struction will be found on pages 00 to 00. 

Third, a loss enters into the calculation where the heating is not con- 
tinuous. This may be referred to as a warming-up loss, or the heat neces- 
sary to raise the air of the enclosure from its initial temperature to the 
desired maintained temperature. It is evident that if only sufficient heat is 
supplied to compensate for the air infiltration and transmission losses, the 
temperature of the enclosure would approach' but not reach the predeter- 
mined temperature, unless additional heat units are supplied for heating an 
amount of air equivalent to the cubic contents of the space to be heated. 
To calculate this loss, the cubic contents of the enclosme, the initial and 
final temperatures of the internal air, and the time desired to raise the air 
through this temperature range must be determined. 

The product of the quantity of air in cubic feet, the density of the air, its 
specific heat, and the temperature difference is the quantity of heat required 
for initial heating of the air. If this quantity be then multiplied by the 
reciprocal of the heating-up period in hours, the product will be the quantity 
of heat that must be supphed per hour during initial heating to supply the 
heat absorbed in heating the air. 

Fourth, a loss or heat requirement should be included in calculations 
where the heating is not continuous, and where large quantities of materials 
such as iron, steel, water, glass, etc., are stored in the enclosure and must be 
heated like the air contents, from their initial to maintained inside temper- 
ature. 

The product of the weight of such material in pounds, its specific heat 
and the desired temperature range is the heat absorbed by the material. 

This quantity must also be multiplied by the reciprocal of the heating- 
up period in hours to obtain the hourly heat requirement during initial 
heating to compensate for this loss or absorption of heat. The longer the 
heating-up period selected the less will be the d Iference in the hourly 
requirements during initial and maintained heating. 

The sum of these foiu- losses gives the total hourly rate at which heat 
must be supplied to maintain the enclosure at a predetermined temperature, 
or to raise the temperature of the enclosure from its initial to predetermined 
temperature, as the case may be. 

Applying this method of calculating the heat loss requirements to the 
house shown, Figure 5-1 represents the main floor of a residence with warm 
basement and second floor. Under these conditions, no ceiling or floor loss 
need be considered. 

The quantities as taken from the plan are given in detail in the Heat- 
loss Computation Sheet, Table 5-1 ; also the basic requirements are given at 
the top of the sheet. 

The losses are figured for each exposed side as in Room No. 1. The 
loss for the north side is 12618 B.t.u., for the east side 9601 B.t.u., for the 
west side 1635 B.t.u. and the B.t.u. required for initial heating of the air 
contents is 623, making a total maximum B.t.u. requirement of 24,477 per 
hour. The heat supply for this room should be placed under the north and 
east windows. The loss for the north and west sides, plus half of the heating- 

5—2 




BUILDING A 



Fig. 5-1. Illustrating method of computing radiator for a residence 

up loss for the air, can be taken care of by one unit placed at the west window. 
The loss for the east side, plus the balance of the heatingrup loss for the air, 
can be taken care of by another unit located at the east window. 

The losses in B.t.u. per hour as taiken from the computation and divided 
in a similar manner are marked on the plan for each room. 

Another illustration of the method of calculation is given in the Heat- 
loss Computation Sheets, Table 5-2, for the factory building shown in 
Figure 5-2. 

The calculation has been separately made for the sections as marked in 
the figure, so that the losses may be proportioned to the exposures. 

In the calculations for section "C," the north and south walls with 
their windows and doors from the floor to line a — b were made separately 
from the balance of the losses for this section. 

As the air infiltration from the upper sash would not be felt directly by 
the operators in the building, the infiltration has been calculated for only 
the west or maximum-wind-velocity side. 

The infiltration factor for the doors has been taken as double that of 
the windows, and in calculating the window infiltration losses only the 
perimeter of the ventilating portion of the window has been considered. 

The requirements for the various walls and sections as taken from the 
calculations are marked on the drawing in their relative locations. 

5—3 







Wind Velocity 






Miles Per Hour 


Outside Temp. 


0° 


N. 20 


Inside Temp. 


70° 


S. 10 


Initial Temp. 


60° 


E. 10 


Heating Period 


IHr. 


W. 20 



Table 5-1. Heat Loss Computation Sheet 



Name: Building A 
Location: 



Loss 


Material 




S 

1! 


1 
? 


1 


as 


cl 

0) 

a 


H> 




Sa 
11 


.00 


a 
■c 

11 
Ota 




i 

HA 


A 

pa 

3W 

js 

H0< 




Room No. 1 


N 

N45° 

N 

N 

E 
E 
E 
E 

E 

W 


"2" 
3 

17' 6" 

2 
■■■2" 

"14"' 

7 

"2" 
'"2" 

25' 6" 
10 

4 
4 

"26" 

2 
"2" 

"is" 
"w" 

"g" 

"2" 
"2" 

2 
2 

38 

10 


2' 4" 
2' 4" 
2' 4" 

1' 9" 
4' 6" 
1' 9" 
4' 6" 
12' 

11' 6" 
11' 
3' 

4' 

4' 

11' 6" 

6' 

2' 

6' 

2' 

23' 

20' 
3' 

3' 

3' 

20' 

12' 6" 

V 6" 

1' 6" 
5' 
14' 
14' 

5' 
5' 

6' 
14' 

1' 

1' 

3' 6" 

3' 6" 

6' 
2' 
6' 
2' 
24' 

2' 6" 

2' 6" 

11' 

11' 

20' 
3' 


6' 
6' 
6' 
9' 

6' 
6' 
6' 
6' 
9' 

9' 
9' 
9' 

6' 
6' 
9' 

6' 
6' 
6' 
6' 
9' 

9' 
9' 

6' 
6' 
9' 
9' 

6' 
7' 
6' 
7' 
9' 
9' 

7; 

9' 
9' 

6' 
6' 
9 
9 

6 
6 

6 
9 

6 
6 
9 
9 

9 
9 


6" 
6" 
6" 
6" 

6" 
6" 
6" 
6" 
6" 

6" 
6" 
6" 

6" 
6" 
6" 

6" 
6" 
6" 
6" 
6" 

6" 
6" 

6" 
6" 
6" 
6" 

6" 
6" 
6" 
6" 
6" 
6" 

6" 
6" 
6" 
6" 

6" 
6" 
6" 
6" 

6" 
6" 
6" 
6" 
6" 

6" 
6" 
6" 
6" 

6" 
6" 


20 

40 
46 
166 

37 
27 
23 
29 
114 

109 
1463 
200 

26 
26 
109 

32 
38 
39 
26 
219 

4845 
285 

100 

78 

190 

2375 

35 
25 
20 
38 
133 
2527 

25 

3S 

57 

2527 

16 

7 

33 

299 

32 
38 
39 
26 
228 

42 
33 
105 
10.=; 

7226 
285 


"46 

■ 
■' 

52 

V- 

"26 

h 
]■ 

' 78 

}■■ 
"58 

"38 

"7 

V- 

65 

"33 

\ 


20 
40 
46 
120 

64 
52 
62 

109 
1663 

26 
26 
83 

32 
38 
65 
154 

5130 

100 

78 

112 

2375 

60 
20 
38 
75 
2527 

25 

38 

19 

2527 

16 

7 

26 

299 

32 
38 
65 
163 

42 
33 
72 
105 

7505 


70 
70 
70 
70 

70 
70 
70 

70 
20 

70 
70 
70 

70 
70 

70 

70 

20 

70 
70 
70 
20 

70 

70 
69 
70 
20 

70 
69 
70 
20 

70 
70 
70 
20 

70 
70 
70 
70 

70 
70 
70 
70 


1 

1 
75 

15 

75 
15 
15 

1 
75 
15 

75 
15 

1 
75 
15 

75 
35 
IS 

1 
35 
15 

1 
75 
15 

75 
15 

1 

15 
8 


75 
75 

85 

24 
75 

85 
85 

24 
75 
24 

85 

24 

75 

24 

75 
24 

85 
85 

.75 
.75 

.24 


87. 7 
87.7 

1 
1 

87.7 
1 

1 

1 
.078 

87.7 
1 
1 

87.7 
87.7 

1 

1 

.078 

87.7 
1 
1 
.078 

87.7 

1 

.98 
1 

.078 

87.7 
.98 

1 
.078 

87.7 
1 
1 
.078 

87.7 
87.7 

1 

1 

87.7 
1 

1 
1 

.078 


".7 
".7 

.7 


3070 
4298 
3450 
1800 
















Wall 


12" Brick, furred and plastered. . . 
Window 


12618 








4771 
3900 
930 






















Wall 


12" Brick, furred and plastered. . 
12" Brick, furred and plastered. . 


9601 






Wall 


1635 
623 

3990 
1950 
1245 


1635 








Air, sp. ht. .24, density .078 




623 




Room No. 2 


N 
N 
N 

E 
E46° 
E 
E 
E 


24477 








Wall 


12'°BriGk, furred and plastered. . 


7185 








2385 
2833 
4875 
2310 






Window 
















Wall 


12''' Brick, fiured and plastered. . 
Air, sp. ht. .24, density .078 


12403 






Initial heating. . . 


1921 

15348 
5850 
1680 
889 




Air, sp. ht. .24, density .078 




1921 




Room No. 3 
Window 


W 
W 
W 


21509 








Will . . - ■ 


12" Brick, furred and plastered. . 
Air, sp. ht. .24, density .078 










Room No. 4 


E 
E 
E 
E 
E 






4473 
1500 
1303 
1125 
946 

3837 
1500 
285 
946 


23767 
















IH" Wood 




W-tU 


12" Brick, furred and plastered. . 




Initial heating.. . 




Room No. S 


W 
W 
W 






9347 




l'.," Wood 




Wall 


12" Brick, furred and plastered. . 
Air, sp ht. .24, density .078 










Room No. 6 


W 

w 
w 






2456 
525 
390 
112 


656S 








Wall 


12" Brick, furred and plastered. . 
Air, sp ht. .24, density .078 




Initial heating. . . 




Room No. 7 


E 
E45° 
E 
E 
E 

W 
W 
W 
W 






2385 
2833 
4875 
2445 


3483 






' 















Wall 


12" Brick, furred and plastered. . 


12538 








6446 
2475 
1080 
840 










Wall 


12" Brick, furred and plastered. . 
28" Brick, furred and plastered. . 

Air, sp. ht. .24, density .078 . . . . . 




Wall 


10841 






Initial heating. . . 
Initial heating. . . 


2810 




Air, sp ht. .24, density .078 




20 1 


2810 












26189 



Note — Where .7 is added as factor in last column of infiltration calculation, this is the sine of 45 deg., the angle at which the wind 
strik s the window. ' 






i ^,2 E ; 



' '^ i = - i '-• "■ 



o 



list"; '^ 



■ E 5 j 



|J° ell 



CO 

o 



03 






d'^ E ; 







Fig. 5-2. Illustrating method of computing radiation in a factory building 







Wind Velocity 






MUes Per Hour 


Outside Temp. 


0° 


N. 20 


Inside Temp. 


65° 


S. 10 


Initial Temp. 


40° 


E. 10 


Heating Period 


2Hr. 


W. 20 



Table 5-2. Heat Loss Computation Sheet 



^ame: Building B 
Location: 



Loss 


Material 


h 


o 

3 g 


■a 


1 


01 ^ 

50. 


g 

S 

Q 




li 

la 


•a- 


a 

o 

■B 

il 

0(K 




h 


■a« 

h 




Section "A" 


w 

w 
w 
w 
w 
w 

N 
N 
N 

S 
S 
S 


10 

' 'id ■ " 

110'' ' 
7 

■ 'io'' ' 

' 30'' ■ 

110' 
110' 
110' 

10 

■ 'id ■ ■ 
lid ■ ■ 

7 
' 30 ' ■ 

■ 30 ■ ■ 

no 
no 
no 

2 

■ ■ '2 " ' 

2 

■ ■ 2 " 

18 
18 

no 

40 

18 

110 

40 

no 
no 
no 


3' 6" 
10' 
7' 
10' 

2'' 6'' 

10' 
10' 

10' 
10' 

30' 
30 
30 

3' 6" 
10' 
7' 
10' 

V 6'' 

10 . 
10 

10 
10 

30 
30 
30 

3' 6" 
10 

7 
10 
40 

3' 6" 
10 
7 
10 

40 

5 
5 

5 

■ 40 ' ■ 
40 
40 


4' 0" 
12' 
8' 
12' 
15' 
15' 

12' 
12' 
16' 

12' 
12' 
16' 

' 16'' ' 

4' 0" 
12' 
8' 
12' 
15' 
15' 

12' 
12' 
16' 

12' 
12' 
16' 

16' 

4 
12 

8 
12 
17 

i 
12 

8 
12 
17 

5' 6" 
5' 6" 

10' 
10' 6" 
5' 6" 

10' 
10' 6" 

27' d'' 


150 
56 
560 
120 
1650 
263 

56 
120 
480 

56 
120 
480 

3300 

3300 

52800 

150 
56 
560 
120 
1650 
263 

56 
120 
480 

56 
120 
480 

3300 

3300 

52800 

30 
56 
112 
120 
680 

30 

56 

112 

120 

680 

378 
495 

1100 
420 
495 

1100 
420 

4400 

4400 
121000 


943 
120 

'lib 

943 

120 
120 

'232 

232 

495 
495 


150 
56 
660 
120 
607 
263 

56 
120 
360 

56 
120 
360 

3300 

3300 

52800 

150 
56 
560 
120 
607 
263 

56 
120 
360 

66 
120 
360 

3300 
3300 
52800 

30 


65 
65 
68 
66 
68 
68 

65 
66 
68 

65 
66 
68 

71 
15 
25 

65 
65 
68 
66 
68 
68 

65 
66 
68 

65 
66 
68 

71 
16 
26 


1.75 
3.5 

75 

30 

22 

35 

3.5 
30 

22 

1.7 
30 
22 

15 
7 
.24 

.85 
1.7 
75 
30 
22 
35 

3.5 

30 
22 

1.7 
30 
22 

15 
7 
.24 

1.75 
3.6 

76 
30 
22 

.85 
1.75 
75 
30 
22 

1.75 
75 
22 
22 
75 
22 
22 
15 

7 
.24 


81.4 

81.4 
.96 
.92 
.96 
.96 

81.4 
.92 
.96 

81.4 
.92 
.96 

1.01 
.18 
.079 

81.4 

81.4 
.96 
.92 
.96 
.96 

81.4 
.92 
.96 

81.4 
.92 
.96 

1.01 
.18 
.079 

81.4 

81.4 
.96 
.92 
;96 

81.4 

81.4 
.96 
.92 
.96 

81.4 
.94 
.9 
.9 
.94 
.9 
.9 
.92 
.18 
.079 


"is 

".5 

".5 


21368 
16954 
40320 

3312 
12820 

8837 






Door 












2" Wood 




Wall . . 






Wall 




102611 




Door 






15954 
3312 
7603 






2" Wood 




Wall 


12" Brick, plain 


26869 










7749 
3312 
7603 






2" Wood. , 




Wall 


12" Brick, plain 


18664 




2" Wood, paper and gravel 






49995 
4158 
12514 








Initial hpating. . . 


Air, sp. ht. .24, density .079 




66667 


Section "B" 


E 
E 
E 
E 

E 
E 

N 
N 
N 

S 

s 
s 






10379 
7749 

40320 
3312 

12820 
8837 


214811 








WinJoiv 






Door 


2" Wood 




Wall 


12" Brick, plain 




Wall 


16" Concrete 


83417 










16954 
3312 
7603 






2" Wood 








26869 










7749 
3312 
7603 




Door 


2" Wood 






12" Brick, plain 


18664 










49995 
4158 
12614 




Floor 


6" Concrete on cinder fill 






Initial heating. . . 


Air, sp. ht. .24, density .079 




66667 


Section "C" lower 


N 
N 
N 
N 
N 

S 

s 
s 
s 
s 

"W 

w 
w 

N 
E 
E 
S 






4274 
1.5964 
8064 
3312 
9462 


195617 






56 65 
112 68 




Window 








2" Wood 




Wall 


12" Brick, plain 


448 

30 

56 
112 
120 

448 

378 

495 

605 

420 

495 

605 

420 

4400 

4400 

121000 


68 

65 
65 
68 
66 
68 

65 
67 
65 
65 
67 
65 
65 
66 
15 
25 


41066 




Window 






2076 
7977 
8064 
3312 
9462 












Single glass 






2" Wood 




Wall 




30891 




Section "C" upper 






53846 
34898 
11979 

8316 
34S9S 
11979 

8316 
60720 

5644 
28677 


71957 






Wall 


12" Brick, plain 




Wall 


12" Brick, plain 










Wall 


12" Brick, plain 




Wall 






Roof . , 


2" Wood, paper and gravel 




Floor 




Initial heatyag.. . 


Air, sp. ht. .24, density .079 
















259173 



CHAPTER VI 
Method of Computing and Selecting Radiation 

DETERMINATION of the radiating surface depends first upon the 
total hourly heat losses, which are assumed to have been calculated 
as described in the preceding chapter. The radiating surface must 
supply enough heat units to compensate for the losses and should be of the 
form that best fits the conditions for the room or enclosure. 

The method of heat supply must first be determined — that is, whether 
the radiation is to be direct, indirect or direct-indirect. The last two methods 
are used principally when ventilation must be considered in addition to the 
heating requirements, although the indirect method is considerably used 
when it is not desired to have the radiation located in the room to be heated. 

Normally, the heat should be supplied at the locations where the greatest 
losses occur, and this is generally at the windows, where in addition to a 
high transmission loss, there is the air infiltration .loss as well. 

Rooms or enclosures where more than one unit of radiation is to be 
installed should have the radiating surface divided in proportion to the 
losses of the spaces served. 

Radiation placed under the windows should not project above the sills, 
should be as wide as the window openings, and should also be installed with 
a 23^-inch space between the wall and the radiation, as this distance gives 
maximum efficiency of heat emission. 

Direct radiation, inasmuch as it is used in a large majority of instal- 
lations, should be considered first. Residences, office, school, library, 
hospital and similar buildings, usually have cast-iron column radiation 
together with some cast-iron wall radiation. Factory and manufacturing 
buildings are usually heated by means of wrought-iron or steel pipe coils or 
cast-iron wall radiation. 




4'^^"^'^^ 



Fig. 6-1. Cast-iron wall radiation on side walls under window, for heating a factory building 



6—1 




Fig. 6-2. Connection to a direct hot-water type radiator showing Webster Modulation Supply Valve and 

Webster Return Trap 

Hot-water pattern radiation is preferable for those Webster systems in 
which Modulation Supply Valves are to be used. The supply valve should 
be placed at the upper inlet and the return trap at the lower opening 
diagonally opposite. 

Good practice in the use of groups of wall radiation suggests that no 
individual group exceed 30 feet in length, as expansion and contraction 
become an important factor on longer runs. Where greater lengths of this 
type of radiation must be used, the supply connection should be made at 
top and bottom and expansion and contraction properly provided for. 

Pipe coil practice demands a spring or mitre piece in the coil to provide 
for expansion and contraction, and the desirable length is limited to sixty 
feet not including the mitre piece. Coils should be securely anchored at the 
return header so as to tlirow the expansion toward the mitre end, the length 
of which should be not less than one-twelfth the coil length for 1-in. pipe 
and one-tenth for 134 -in. or 13'2-in. pipe. 

The amoxmt of heat emitted from any given type of direct radiation is 
usually stated in B.t.u. per hour per square foot of radiator surface. This 
heat is given off in two ways, by convection directly to the air which passes 

6—2 



over the heated surface, and by radiation directly to surrounding materials 
independent of that carried off by the air. The heat given off by radiation 
does not heat the air through which it passes, but travels in straight lines 
and heats the materials on which it impinges. 

After selecting the type of radiation best suited for the particular case, 
the number of square feet of radiating surface required should be deter- 
mined next. The total number of heat units that must be supplied per hour 
divided by the heat units emitted per hour per square foot of radiation 
gives the required surface in square feet of radiation. 

Table 6-1 will be of assistance in determining the heat emitted by dif- 
ferent types of radiation. 

Table 6-1. B. t. u. Emitted per Hour per Square Foot of Radiating Surface* 

Radiators Ten Sections Long 

Steam Temperature 215 deg. fahr. Room Temperature 70 deg. fahr. 













Ratio of 


Percent 


Number 


Height 


B.t.u. 


B.t.u. 


Total 


Radiating 


Convected 


of 


of 


by 


by 




to Total 


heat of 


Columns 


Radiator 


Convection 


Radiation 


B.t.u. 


Surface 


Total heat 



One 


38 in. 


150 


106 


256 


0.53 


58.6 


" 


32 in. 


158 


108 


266 


0.54 


59.4 


" 


26 in. 


162 


111 


273 


0.555 


59.4 


'■' 


23 in. 


160 


119 


279 


0.595 


57.4 


** 


20 in. 


166 


117 


283 


0.584 


58.7 


Two 


45 in. 


148 


86 


234 


0.43 


63. 


" 


38 in. 


148 


92 


240 


0.458 


62. 


" 


32 in. 


154 


94 


248 


0.47 


62. 


" 


26 in. 


149 


106 


255 


0.53 


58. 


" 


23 in. 


151 


109 


260 


0.544 


58. 


** 


20 in. 


153 


112 


265 


0.56 


58. 


Three 


45 in. 


142 


76 


218 


0.382 


65. 


" 


38 in. 


147 


79 


226 


0.394 


65. 


" 


32 in. 


158 


75 


233 


0.375 


68. 


" 


26 in. 


166 


75 


241 


0.376 


69. 


" 


22 in. 


166 


82 


248 


0.407 


67. 


" 


18 in. 


162 


92 


254 


0.46 


64. 


Four 


45 in. 


149 


56 


205 


0.28 


73. 


" 


38 in. 


150 


60 


210 


0.30 


71.5 


" 


32 in. 


151 


66 


217 


0.331 


69.5 


" 


26 in. 


155 


70 


225 


0.35 


69. 


" 


22 in. 


156 


76 


232 


0.382 


67. 




18 in. 


151 


87 


238 


0.435 


63.5 


Wall Radiation 


3 in. wide 


14 in. 


152 


171 


323 


0.8.54 


47. 


" " 


22 in. 


154 


156 


310 


0.78 


49.7 


'* '* 


29 in. 


138 


157 


295 


0.784 


48. 


Pipe Coil 


6-l}4 in. Pipes 
8-1 M in. " 
10-1 }i in. " 
12-1 1^ in. " 






360 
343 
330 
319 







* John R. AUen A. S. H. & V. E. Journal— January 1920. 



From Table 6-1 it will be noted that low, narrow radiation is most 
efficient and that the efficiency decreases as the height and width increase. 

A number of factors other than variation of the height and width of 
section vary the amount of heat emitted from radiation. Some of these 

6—3 




Fig. 6-3. Arrangement of cast-iron wall radiation on side wall of a factory building. 



-rou 


























1 
















+50 


















































































J +40 


















































































S43O 












































\ 






































C= 


-|+20 




\ 








































\ 


y 




































J2 

S +10 






\ 

























































































^^ 























































■ 




■ . 






















—in 











































1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 

Length of Radiator in Sections 

Fig. 6-4. Percentage of variation in heat emitted by cast-iron radiation per square foot due to variation 

in the number of sections from a standard 10-section radiator 
6—4 



factors and their effect upon the efficiency of the radiation are worthy of 
further explanation. 

The preceding table is based upon a radiator ten sections wide. As the 
number of sections decrease, the efficiency increases, due to increase of the 
mjre efficient end section surface in proportion to total radiator sm"face; 
also a short radiator emits proportionally more radiant heat than a longer 
one. Figure 6-4 shows the effect of varying the number of sections, and 
that increasing the number of sections above ten has not as much effect as 
decreasing the number below ten. It will also be noted that a four-section 
rad'ator will give off about ten per cent more heat per square foot of surface 
than one ten sections long. 



290 
280 
270 
260 

^ 250 

T 

= 240 

oz 

-5 230 
E 

o5 

-220 






















■■ 




/ 






















/ 


























^ 












































/ 


























/ 
























/ 
























/ 


/ 












' 












/ 
















S 210 
200 
190 
180 
T70 




























































/ 
























/ 


























^ 






















/ 



























-40 -30 -20 -10 +10 +20 +30 +40 +50 +60 

Percentage Variation in Heat Emission 

Fig. 6-5, Percentage variation in heat emitted by radiation by varying 
the steam temperatm'e from 215 deg. fatir. 



+70 



+ 80 



6—5 



When the temperature of steam in the radiation is considered at 215 
deg. fahr. as standard, the effect upon the heat emission of radiation due 
to varying tliis temperature is shown in Figure 6-5. The percentage varia- 
tion can be read directly from the cm-ve. 

Example: If steam at a temperature of 230 deg. fahr. is supplied to 
the radiator, the heat emission will be increased twelve per cent over one 
upphed with steeun at 215 deg. fahr. 



T'i-v 




. 


^^ 


V 


-^ V ^ 


^^ 


"^^ 


= ^^ - 


"^j-in _ _ ^ 


•<»+io _ 's : 


~ ^^ - : 


E ^s^ 


^ . ^i _ 


^^ 


s ^^ 


= - !=.= 


^i 


~ '^^ 


_ n ..-5.. -- - --It 


g '-:<:; 


- ^K 


-" " ^ 


S - ^^ 


> - - ^v 


» ^ it 


a _ _ ^^ _J_ 


■o V 


= " ■^^ 


S in - ^v - 


S ^^ 


i£ ^v 


^s 


^v 


vt- 


^b. 


!j5^ 


s 


•^^ 


^•jn . ii 



40 50 60 70 80 90 100 110 

Room or Surrounding Temperature -Deg. Fahr. 

Fig. 6-6. Percentage variation in heat emitted by radiation by varying 
the room temperature from 70 deg. fahr. 

The surrounding or room temperature is taken at 70 deg. fahr. as a 
standard — the effect upon the heat emitted by radiation, due to varying 
this temperatvu-e is shown graphically in Figure 6-6. From the curve it 
will be observed that, for instance, a radiator in a room temperature of 60 
deg. falir. will emit 6 per cent more heat than w ill same radiator in a room 
temperature of 70 deg. fahr. 

The effect on heat emission due to variation in steam temperature is 
much greater than an equal temperature variation in the surrounding or 
room temperature. 

The following example will illustrate the use of the curves in Figures 
6-4, 6-5 and 6-6 for determining the heat emission under given conditions. 
It is desired to know the B.t.u. emitted per hour per square foot of radiating 
surface of a standard cast-iron radiator, two columns wide, 38 inches high, 
and six sections long when supphed with steam at 240 deg. fahr. and located 
in a room heated to 80 deg. fahr. 

Referring to Table 6-1, a radiator as above except that it is ten sections 
long, with steam at 215 deg. fahr. in room temperature 70 deg. fahr. gives 
off 240 B.t.u. per hour per square foot. A radiator six sections long is 4.5 
per cent, more efficient (Figure 6-4) when supphed with steam at 240 deg. 

6—6 



fahr., the efficiency is increased 20 per cent (Figure 6-5), and if located in a 
room heated to 80 deg. fahr. there is a decrease in efficiency of 6 per cent 
(Figure 6-6). The heat emission of the radiator required would be 240 x 
1.045 X 1.20 X 0.94, or 283 B.t.u. per lir. per sq. ft. of radiation surface. 

Painting the radiator affects only the heat emitted by radiation, and 
h'as practically no effect upon the convected heat. As painting affects only 
the surface, the final coat is the only one that must be considered. Paints 
generally produce only a very slight effect. That of flake metals is more 
marked. (See Table 6-2.) 

Table 6-2. Approximate Effect of Painting on the Total Heat Emission of 
Radiators. Test made on a 2-column Radiator 33 Inches High and 
Ten Sections Long, Supplied with Steam at 215 deg. fahr. in 
Room Temperatm-e of 70 deg. fahr. 

Cast Iron Base 100% Painted Maroon Japan 100% 

Painted with Aluminum Bronze 83% Painted with White Zinc Paint 101% 

Painted with Gold Bronze 85% Painted with No-lustre Green Ejiamel 96% 

Painted White Enamel 101% 

Direct radiators are sometimes set behind grilles or screens, in window 
enclosures or wall recesses, aU of which greatly decrease the efficiency of 
the radiation. 

Tests by Professor Brabbee, as reported by George Stumpf, Heating 
and Ventilating Magazine, May, 1914, show that a radiator in an enclosure 
is most efficient when located with 2X4 inches between the wall and radiator 




Fig. 6-7. An enclosed radiator having grilles or screens on front and top of enclosure. The 
Modulation Supply Valve Control is shown located on top of enclosure 



6—7 



4-= 

r 

I-- 



-0— >l 






,0. 



U 



I 



mM///////////////yW/ 
Fig. 6-8 




r 






A 



U 






Fig. 6-9 



W/^////////////////M// 
Fig. 6-10 



^ 



'y ^///////////A I 
1 .-Tx^-y- 



I 

! 

I 



U 



Fig. 6-11 



I 
1^ 



d 



-Metal 
Shield 



Fig. 6-12 



T 

I 




Fig. 6-13 



i 






c\r\ 



\\J 



\J 



r\ 



A 



A 



w 



A 



V7 



W 



Enclosures for radiators 



Length of all outlets "O" = length of radiator. 

Length of all inlets "I" = length of radiator. 

Width of ail outlets "O" = width of radiator or as 
given in table. 

Screens or grilles have 44 per cent, free area. . 



6—8 



and between the inside of the enclosure and the radiator. Abstracts from 
these tests follow. 

The inlet and outlet openings of any form of enclosure should extend at 
least the entire length of the radiator. The width of the outlet is usually 
made that of the radiator. Tests show little gain in efficiency for wider 
outlets, but a decrease of about five per cent for each inch narrower than 
that of the radiator. 

The outlets and inlets in Tables 6-3 to 6-8 are the full length of the radi- 
ators. The width of outlet " " is the width of the radiator except in Table 
6-4, where it is as given. The width of inlet "I" is as stated in the Tables. 
Both openings axe covered with screen of 44 per cent free area. 

The design of the screen or grille has no effect provided the free area 
is not changed. 

Figure 6-8 shows a form of enclosure frequently used. 

Table 6-3. Decrease in Radiator Efficiency with Form of Enclosure Shown 

in Fig. 6-8. 



Radiator Width 


Radiator Height 


Width of I 


Decrease in Efficiency 


Two-column 


42 in. and over 


9 in. 


15% 


" " 


Under 42 in. 


9 in. 


20% 


" " 


Under 42 in. 


5 in. 


25% 


Three-column 


42 in. and over 


9 in. 


15% 


" " 


32 in. to 38 in. 


9 in. 


15% 


" " 


32 in. to 38 in. 


Tin. 


20% 


" " 


26 in. and under 


9 in. 


20% 




26 in. and under 


5 in. 


25% 



If the width of inlet is made proportional to the free area and not 
screened, the efficiency reduction will remain as above. 

Another form of enclosure, Figure 6-9, gives the effect upon the radi- 
at-on efficiency as shown in Table 6-4. 

Table 6- 3. Decrease in Radiator Efficiency with Form of Enclosure Shown 

in Fig. 6-9. 



Radiation Width 


Radiation Height 


Width of O 


Width of I 


Decrease in Efficiency 


Two-column 
Three-column 


42 in. and over 
32 in. to 38 in. 
32 in. to 38 in. 
26 in. and under 

26 in. and over 
26 in. and over 


Sin. 
9 in. 

7 in. 
6 in. 

9 m. 
6 in. 


8 in. 

9 in. 
7 in. 
6 in. 

9 in. 
6 in. 


20% 
20% 
25% 
33% 

20% 
25% 



Enclosure of the form shown in Figure 6-10 is sometimes used and by 
test gives the following effect: 

Table 6-5. Decrease in Radiator Efficiency with Form of Enclosure Shown 

in Fig. 6-10. 



Perforated screen full front of enclosiu'e — decrease in efficiency 20% 

Same screen with deflector — " " " 15% 



6—9 




Fig. 6-15. An enclosed radiator in a window seRt, with grilles of rattan cane. The Modulation 
Supply Valve control is placed on the window seat. 

If an outlet "0" is provided and made equal to the width and length 
of the radiator, the efficiency decreases 10%. 

Sometimes it is desirable to set the radiators in wall recesses, as shown 
in Figure 6-11, which causes a decrease in efficiency as follows: 

Table 6-6 Decrease in Radiator Efficiency Due to Wall Recess (Fig. 6-11) 

When = 1J^ inches — decrease in efficiency 11% 

" = 3 " " " " 7.3% 

" = 4 " " " " 6% 

The distance "a" has little or no effect, and, therefore, need only be 
sufficient for connections to the radiator. 

A shield in front of a radiator as shown in Figure 6-, 12 increases the 
radiator efficiency as follows: 

Table 6-. Increase in Radiator Efficiency by Use of a Shield (Fig. 6-12) 

Height of shield, H 52 in. 52 in. 52 in. 72 in. 

Width of open slot, 1 6J^ in. 9 in. 12 in. 12 in. 

Increase in efficiency 2.2%, 6.3% 12.5% 13% 

. Another form of enclosure, shown in Figure 6-13, by test gives the fol" 
lowing effect upon the radiator efficiency : 

Table 6-8. Decrease in Radiator Efficiency with Form of Enclosure Shown 

in Fig. 6-13 

Width D 

8 in. 
6 in. 
5 in. 
4 in. 
3 in. 

6—10 





Percent Decrease 


Width D 


m 


Efficiency 


Sin. 




10 


6 in. 




15 


5 in. 




20 


4 in. 




25 


3 in. 




33 



Ceiling Line 



yr WEBSTER RETURN TRAP 
Place same above hiohest — 
Point ot Dry Return 



/4" Air Line inlo Top ot 
Dry Return. M"when Dry 
Return is over 10' 0" 
Distant 




Dry Return 



Supply Main 



Indirect Radiator 
Parts ot Ca5ln[! removed 

12"x 12"SlidinG Door at 
Bottom oi Casing 




Full size Nipple to outside of Radiator 
Casing, ttian a tull size Ell and Nipple 
connecting to a reducing Tee fjot less ttian H 

Union above Water Line of Boiler- 
Water Line of Boiler -^^ 

'a 



Connect into Wet Return Main- 



Fresti Air 



Quadrant Damper 
Clean Out Door 



Special Swing Check Valve 
Tfiis Connection to be on the same Centre as Wet Return — — ^ \ 



Wet Return near Floor 



^ZL 



Fig. 6-16. Connections to an indirect radiator 

Indirect radiation generally refers to that located below and outside of 
the room to be heated. (See Figure 6-16.) The heat is deUvered to the room 
by a system of ducts that convey fresh air from outside. The air passes 
over the radiation, is heated and then discharged into the room through 
register faces located in the room floor or wall. This method of heating is 
called fresh air indirect, as a constant supply of fresh heated air is delivered 
into the room. 

Where the air supply is taken from the room, passed over the heating 
surface and then discharged into the room again, the method is referred to 
as recirculating indirect. 

In either system no radiation is located in the room to be heated. 

The indirect method of heating is most used in the principal rooms of 
residences, clubs, churches and similar types of buildings, and is much 
more expensive to install and to operate than is the direct system. 

All rooms heated by the fresh air indirect system must be provided 
with vents for the escape of the air replaced by that delivered by the "indirect 
stack," as this radiation is often called. 

6—11 



Many variable factors, each of prime importance, enter into an accurate 
calculation of the proper proportions of a system of this type. These vari- 
ables include velocity and direction of the wind, frictional resistance to the 
air flow In the ducts, and the loss of heat due to transmission through the 
w afls of hot air ducts. 

Each manufacturer of radiation for this system has his o^n special 
design, which is usually sold by catalogue ratings in square feet of surface. 
Reliable data as to the free area between sections and the heating effect 
under the variable conditions of steam and air temperatures at various air 
velocities are unfortunately not available for each make of radiation used in 
this method of heating. Proper values are very difficult to assign to the 
variable factors, and the several rules for determining the proper propor- 
tions of such a system are all based upon some standard conditions and 
assumptions. 

The general principle of this system is that the air be delivered to the 
room at a tempera tiu-e higher than that of the room, and in such volume 
that in cooling to room temperature, sufficient heat units are given up to 
replace those lost by transmission, infiltration and otherwise. 

The requirements for this method of heating are usually computed in 
the following way: 

First: Calculate the total heat losses in B.t.u. per hour for the room to 
be heated as described in Chapter 5. 

Second: Determine the height of the column of heated air, that is, the 
distance from center of indirect stack to center of the room register. 

Third: Assume the temperature of the air entering the room. This is 
usually taken about 120 deg. fahr. when air enters the radiator at zero and 
the radiator is supplied with steam at atmospheric pressure or slightly above. 

Fourth: Determine the velocity of air due to difference in densities 
between the heated and outside air for a column equal in height to that 
found. 

Fifth: Ascerta'n from the manufactiu-er of the type of radiation selected 
the velocity at which air must pass through the radiator to produce the final 
temperature selected, when the radiator is supplied with steam at a pre- 
determined temperature and air enters the heating stack at the minimum 
outside temperature. Ascertain also the temperature of the air on which 
this performance is based, the free area between the sections, and the 
number of square feet of heating surface per section. 

With this data the amount of radiation may be determined as follows : 

H = total B.t.u. losses per hour for the room. 

ti = temperature of air entering the room. 

tr = temperature of air in room (room temperature) . 

tp = temperature of air on which radiation performance is based. 

d = density of air at temperature tp. 

V = performance velocity of air in feet per minute. 

a =l"ree area per section of radiation. 

H 
-^r; — , , „ = pounds of air required per minute = P 
.24 [trir) 60 '^ 

6-12 i 



where .24 is the specific heat of the air. 

P 

T= Cubic feet of air per minute at tp. 

p 

J divided by av = number of sections of radiation required from which 

the square feet of radiation can be determined. 
The sizes of the ducts or flues for conveying the air to and from the 
heating surface are dependent upon the velocity of the air due to the 
unbalanced air column. This velocity may be determined theoretically 
from the formula: 



v=48oVAli^ 

460 plus t 

in which 

V = velocity in feet per minute. 

h = height of warm air column in feet or distance from center of heating 

surface to center of register. 
t = average temperature of air in column, 
to = average temperature of outside air. 

To allow for friction in ducts, through heating surface, register face 
and elsewhere, velocities of one-third of the theoretical may be assumed. 

The area of the hot-air duct may be determined as follows : 

* • . , 144P 

Area m square mches = —^ — 

in which 

P = pounds of air required per minute. 

d = density of air at average temperature in hot air duct. 

V = velocity in feet per minute in duct. 

The register should have a free area equal to the area of the hot-air 
duct. The area of the cold-air duct can be determined in a manner similar 
to the hot-air duct area, using density of the air at the cold inlet temperature. 

Direct-indirect radiation, as the name implies, consists of radiators 
arranged so that a portion of each serves on the indirect principle and the 
remainder as a direct radiator ; the entire surface, however, is located in the 
r3om to be heated. This combination is accomplished by providing a direct 
radiator and installing a metal box base under some of the sections. Cold 
fresh air is taken from the outside of the building directly through the wall 
and connected to this box base. The fresh air passes up through its portion of 
the radiator into the room. The balance of the section acts as plain direct 
radiation. 

This method of heating has come into quite general use in recent years 
in some localities where the state ventilation laws for public buildings specify 
either the quantity of air to be supplied per minute per person, or the nmnber 
of square inches of fresh-air inlet duct per person. The latter requirement 
can be met by this type of radiation. 

6—13 



The size of the opening in the wall or the waU box determines the size 
of the box base, and the number of sections of the radiator enclosed by the 
box base are to be considered as available only for heating the incoming air. 

Sufficient additional direct heating surface must be provided, either by 
adding sections to the radiator, extending same outside of the box base on 
either end, or by installing separate units for supplying the heat required 
to compensate for the losses through wall, glass, and through infiltration, 
as already mentioned. 

Vent flues must be extended from all rooms heated and ventilated by 
this method. 

In order to obtain the desired air movement and prevent back draft in 
the flues, they must be provided with aspirating radiation or rotary type 
ventilators. 

The radiation best suited for direct-indirect surface is that with high 
and wide sections. One manufacturer of the most modern devices for this 
type of system gives the size of the ventilating base, together with its capac- 
ity, fresh cdr inlet area emd amount of radiating surface to be enclosed as 
given in Table 6-9. 

Table 6-9 . Dimensions of Direct-indirect Radiation Surface as given by one 
manulacturer . Not standard with other builders 





Capacity 


in 


Area of Fresh 




Size of Wall Box 


Cu. Ft. per 


Min. 


Air Opening 


Radiating Sxuface 


8 in. X 20 in. 


180 




120 


50 


8 in. X 24 in. 


240 




144 


,50 


8 in. X 30 in. 


300 




180 


60 


103^ in. X 20 in. 


270 




160 


50 


1034 in. X 24 in. 


330 




192 


60 


103^ in. X 30 in. 


420 




240 


60 



As an example of the application of Table 6-9, select and compute the 
radiation to supply the heat requirements as shown for the various rooms 
in Figure 5-1, page 5-3, based on steam at 215 deg. fahr., or 1 lb. per sq. in. 
pressure. 

Room No.- 3 requires a total of 23767 B.t.u. per hour and is to be heated 
by means of direct radiation. The window siUs are 24 inches high. There- 
fore, 23-inch high radiators should be installed. For a room of this size, it 
appears that two-column radiation should give sufficient surface. The 
B.t.u. emitted by two-column, 23-inch high radiation is given in Table 6-1 
as 260 B.t.u. per hr. per sq. ft. of surface. As these radiators will be twenty 
sections long instead of the standard ten, on which the above efficiency was 
based, the efficiency, or B.t.u. emitted wiU be reduced by 3.5 per cent, 
making an actual efficiency of 251. This divided into the total heat require- 
ments gives 93 square feet of radiation required, which is supphed by two 
units of 46% square feet each as marked on the plan. 

Data as above for determination of the other units are marked on the 
plan. Room No. 7, which is to be heated by indirect surface, is calculated 
as follows: The total requirements for the west side are 13943 B.t.u. per hr., 

6—14 



and assuming that the air enters the room at 120 deg. fahr., the pounds of 
air required in accordance with formula on page 6-12 would be 19.4 per minute. 

Vento radiation 30 inches long on 4-inch centers gives a temperature 
rise of air from zero to 120 deg. fahr. at 100 ft. per min. velocity measured 
at 70 deg. fahr. volume. The free area per section is .225 sq. ft. 

The pounds of air as found above divided by the density at 70 deg. 
fahr., or .0749, gives 259 cu. ft. of air per minute. 

This volume divided by the velocity, then by the free area per section, 
gives 12 sections required. 

The distance from the center of the radiation to the floor above is 27 
inches, which head with 120 deg. fahr. temperature difference gives a theo- 
retical velocity of 367 feet per minute by the formulae on page 6-13. For 
determining the size of the ducts, one-third of this value, or 122 ft. per min. 
velocity may be used. 

Using formula on page 6-13 with a density for air at 120 deg. fahr., the 
area of the hot-air duct is 335 sq. in. The register if of 66% per cent 
free area should contain 503 square inches. 

The cold-air duct by the above formula, using air density at zero, 
should have a sectional area of 266 sq. in. 

The indirect surface for the requirement of the east side of this room 
was calculated similarly. 

As another example, determine the necessary radiation to supply the 
heat required for the factory building as calculated in the previous chapter 
and shown in Figure 5-2, page 5-5. 

Assume that steam at 10 lb. per sq. in. pressure or at a temperature of 
240 deg. fahr. is available for heating this building under maximum load 
conditions. The increase in B.t.u. emission of the heating surfaces for this 
increased temperature above the standard or basic temperature is 20 per 
cent, and there would be a further increase in efficiency of 3 per cent due 
to a 65-deg. fahr. instead of 70-deg. fahr. room temperature. 

This would make a total increase of 23.6 per cent in the B.t.u. emitted 
per hour per sq. ft. of radiation for this installation, over the basic value. 

The monitor portion of the building is provided with 134-inch pipe 
coils under the windows, with expansion springs at the ends, as shown. For 
the lower portion of the building cast-iron wall radiation is to be installed, 
as shown. The efficiency and method of determining the amount of surface 
are shown on the plan. 



6—15 



Table 6-10. Surface in square feet of one to twelve ll4.-inch pipe coils, 
1 to 100 feet long 













NUMBER OF 


1M"»PIPES 










Length 


























of Coil 




























1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


1 


.43 


.86 


1.29 


1.72 


2.15 


2.58 


3.01 


3.44 


3.87 


4.30 


4.73 


5.16 


2 


1 


2 


3 


3 


4 


5 


6 


7 


8 


9 


9 


10 


3 


1 


3 


4 


5 


6 


8 


9 


10 


12 


13 


14 


15 


4 


2 


3 


5 


7 


9 


10 


12 


14 


15 


17 


19 


21 


5 


9 


4 


6 


9 


11 


13 


15 


17 


19 


22 


24 


26 


6 


3 


5 


8 


10 


13 


15 


18 


21 


23 


26 


28 


31 


7 


3 


6 


9 


12 


14 


18 


21 


24 


27 


30 


33 


36 


8 


3 


7 


10 


14 


17 


21 


24 


28 


31 


34 


38 


41 


9 


4 


8 


12 


15 


19 


23 


27 


31 


35 


39 


43 


46 


10 


4 


9 


13 


17 


22 


26 


30 


34 


39 


43 


47 


52 


11 


5 


9 


14 


19 


24 


28 


33 


38 


43 


47 


52 


57 


12 


5 


10 


15 


21 


26 


31 


36 


41 


46 


52 


57 


62 


13 


6 


11 


17 


22 


28 


34 


39 


45 


50 


56 


61 


67 


14 


6 


12 


18 


24 


30 


36 


42 


48 


54 


60 


66 


72 


15 


6 


13 


19 


26 


32 


39 


45 


52 


58 


65 


71 


77 


16 


7 


14 


21 


28 


34 


41 


48 


55 


62 


69 


76 


83 


17 


7 


15 


22 


29 


37 


44 


51 


58 


66 


73 


80 


88 


18 


8 


15 


23 


31 


39 


46 


54 


62 


70 


77 


85 


93 


19 


8 


16 


25 


33 


41 


49 


57 


65 


74 


82 


90 


98 


20 


9 


17 


26 


34 


43 


52 


60 


69 


77 


86 


95 


103 


21 


9 


18 


27 


36 


45 


54 


63 


72 


81 


90 


99 


108 


22 


9 


19 


28 


38 


47 


57 


66 


76 


85 


95 


104 


114 


23 


10 


20 


30 


40 


49 


59 


69 


79 


89 


99 


109 


119 


24 


10 


21 


31 


41 


52 


62 


72 


83 


93 


103 


114 


124 


25 


11 


22 


32 


43 


54 


65 


75 


86 


97 


108 


118 


129 


26 


11 


22 


34 


45 


56 


67 


78 


89 


101 


112 


123 


134 


27 


12 


23 


35 


46 


58 


70 


81 


93 


104 


116 


128 


139 


28 


12 


24 


36 


48 


60 


72 


84 


96 


108 


120 


132 


144 


29 


12 


25 


37 


50 


62 


75 


87 


100 


112 


125 


137 


150 


30 


13 


26 


39 


52 


65 


77 


90 


103 


116 


129 


142 


155 


31 


13 


27 


40 


53 


67 


80 


93 


107 


120 


133 


147 


160 


32 


14 


28 


41 


55 


69 


83 


96 


110 


124 


138 


151 


165 


33 


14 


28 


43 


57 


71 


85 


99 


114 


128 


142 


156 


170 


34 


15 


29 


44 


58 


73 


88 


102 


117 


132 


146 


161 


175 


35 


15 


30 


45 


60 


75 


90 


105 


120 


135 


151 


166 


181 


36 


15 


31 


46 


62 


77 


93 


108 


124 


139 


155 


170 


186 


37 


16 


32 


48 


64 


80 


95 


111 


127 


143 


159 


175 


191 


38 


16 


33 


49 


65 


82 


98 


114 


131 


147 


163 


180 


196 


39 


17 


34 


50 


67 


84 


101 


117 


134 


151 


168 


184 


201 


40 


17 


34 


52 


69 


86 


103 


120 


138 


155 


172 


189 


206 


41 


18 


35 


53 


71 


88 


106 


123 


141 


159 


176 


194 


212 


42 


18 


36 


54 


72 


90 


108 


126 


144 


163 


181 


199 


217 


43 


18 


37 


55 


74 


92 


111 


129 


148 


166 


185 


203 


222 


44 


19 


38 


57 


76 


95 


114 


132 


151 


170 


189 


208 


227 


45 


19 


39 


58 


77 


97 


116 


135 


155 


174 


194 


213 


232 


46 


20 


40 


59 


79 


99 


119 


138 


158 


178 


198 


^8 


237 


47 


20 


40 


61 


81 


101 


121 


141 


162 


182 


202 


222 


243 


48 


21 


41 


62 


83 


103 


124 


144 


165 


186 


206 


227 


248 


49 


21 


42 


63 


84 


105 


126 


147 


169 


190 


211 


232 


253 


50 


22 


43 


65 


86 


108 


129 


151 


172 


194 


215 


237 


258 



6—16 



Table 6-10. Surface in square feet of one to twelve li/^-inch pipe coils, 
1 to 100 feet long. (Continued) 













NUMBER OF IH" PIPES 










Length 


























of Coil 




























1 


2 


3 


4 


S 


6 


7 


8 


9 


10 


11 


12 


51 


22 


44 


66 


88 


110 


132 


154 


175 


197 


219 


241 


263 


52 


22 


45 


67 


89 


112 


134 


■157 


179 


201 


224 


246 


268 


53 


23 


46 


68 


91 


114 


137 


160 


182 


205 


228 


251 


273 


54 


23 


46 


70 


93 


116 


139 


163 


186 


209 


232 


255 


279 


55 


24 


47 


71 


95 


118 


142 


166 


189 


213 


237 


260 


284 


56 


24 


48 


72 


96 


120 


144 


169 


193 


217 


241 


265 


289 


57 


25 


49 


74 


98 


123 


147 


172 


196 


221 


245 


270 


294 


58 


25 


50 


75 


100 


125 


150 


175 


200 


224 


249 


274 


299 


59 


25 


51 


76 


101 


127 


152 


178 


203 


228 


254 


279 


304 


60 


26 


52 


77 


103 


129 


155 


181 


206 


232 


258 


284 


310 


61 


26 


52 


79 


105 


131 


157 


184 


210 


236 


262 


289 


315 


62 


27 


53 


80 


107 


133 


160 


187 


213 


240 


267 


293 


320 


63 


27 


54 


81 


108 


135 


163 


190 


217 


244 


271 


298 


325 


64 


28 


55 


83 


110 


138 


165 


193 


220 


248 


275 


303 


330 


65 


28 


56 


84 


112 


140 


168 


196 


224 


252 


280 


307 


335 


66 


28 


57 


85 


114 


142 


170 


199 


227 


255 


284 


312 


341 


67 


29 


58 


86 


115 


144 


173 


202 


230 


259 


288 


317 


346 


68 


29 


58 


88 


117 


146 


175 


205 


234 


263 


292 


322 


351 


69 


30 


59 


89 


119 


148 


178 


208 


237 


267 


297 


326 


356 


70 


30 


60 


90 


120 


151 


181 


211 


241 


271 


301 


331 


361 


71 


31 


61 


92 


122 


153 


183 


214 


244 


275 


305 


336 


366 


72 


31 


62 


93 


124 


155 


186 


217 


248 


279 


310 


341 


372 


73 


31 


63 


94 


126 


157 


188 


220 


251 


283 


314 


345 


377 


74 


32 


64 


95 


127 


159 


191 


223 


255 


286 


318 


350 


382 


75 


32 


65 


97 


129 


161 


194 


226 


258 


290 


323 


355 


387 


76 


33 


65 


98 


131 


163 


196 


229 


261 


294 


327 


359 


392 


77 


33 


66 


99 


132 


166 


199 


232 


265 


298 


331 


364 


397 


78 


34 


67 


101 


134 


168 


201 


235 


268 


302 


335 


369 


402 


79 


34 


68 


102 


136 


170 


204 


238 


272 


306 


340 


374 


408 


80 


34 


69 


103 


138 


172 


206 


241 


275 


310 


344 


378 


413 


81 


35 


70 


104 


139 


174 


209 


244 


279 


313 


348 


383 


418 


82 


35 


71 


106 


141 


176 


212 


247 


282 


317 


353 


388 


423 


83 


36 


71 


107 


143 


178 


214 


250 


286 


321 


357 


393 


428 


84 


36 


72 


108 


144 


181 


217 


253 


289 


325 


361 


397 


433 


85 


37 


73 


110 


146 


183 


219 


256 


292 


329 


366 


402 


439 


86 


37 


74 


111 


148 


185 


222 


259 


296 


333 


370 


407 


444 


87 


37 


75 


112 


150 


187 


224 


262 


299 


337 


374 


412 


449 


88 


38 


76 


114 


151 


189 


227 


265 


303 


341 


378 


416 


454 


89 


38 


77 


115 


153 


191 


230 


268 


306 


344 


383 


421 


459 


90 


39 


77 


116 


155 


194 


232 


271 


310 


348 


387 


426 


464 


91 


39 


78 


117 


157 


196 


235 


274 


313 


352 


391 


430 


470 


92 


40 


79 


119 


158 


198 


237 


277 


316 


356 


396 


435 


475 


93 


40 


80 


120 


160 


200 


240 


280 


320 


360 


400 


440 


480 


94 


40 


81 


121 


162 


202 


243 


283 


323 


364 


404 


445 


485 


95 


41 


82 


123 


163 


204 


245 


286 


327 


368 


409 


449 


490 


96 


41 


83 


124 


165 


206 


218 


289 


330 


372 


413 


454 


495 


97 


42 


83 


125 


167 


209 


250 


292 


334 


375 


417 


459 


501 


98 


42 


84 


126 


169 


211 


233 


295 


337 


379 


421 


464 


506 


99 


43 


85 


128 


170 


213 


255 


298 


341 


383 


426 


468 


511 


100 


43 


85 


129 


172 


215 


258 


301 


344 


387 


430 


473 


516 



6—17* 



CHAPTER VII 

Ventilation Problems as They Aflfect the Design of Webster 
Heating Systems 

VENTILATION in the past was based on more or less traditional 
and unscientific standards, but is now receiving more of the con- 
sideration warranted by its importance. 

The necessity of providing adequate ventilating facilities for public 
buildings and buildings for various classes of industrial operations has been 
recognized by the legislative bodies of numerous states and cities, which 
have passed laws and ordinances governing the quantity of air to be supplied 
per person, and in some instances also the locations from which the air supply 
is to be brought into the room and the vitiated air removed. 

Ventilation is cla«;sed, and rightly so, as a branch of applied science, 
and it is the duty of the ventilating engineer to apply the pr'nciples of this 
science to the problems with which he is dealing in such a manner that the 
results obtained will produce the most healthful and comfortable conditions 
in the ventilated rooms. 

A ventilating system may be very satisfactory in regard to the quantity 
and means of distribution of the air but still fail to produce healthful and 
comfortable conditions. A good ventilating system should produce im- 
mediate physical comfort. The human body is the best indicator as to 
whether or not these conditions are realized. 

Temperature and relative humidity are important factors in producing 
comfort ; the human body is to a great extent influenced by the temperature 
of the surrounding air, and by the rate at which perspiration is evaporated 
from the body into the air, which again is influenced by the relative humidity 
of the air. 

It is generally considered that the dry-bulb temperature to produce a 
sense of comfort to a person at rest is 68 to 70 deg. fahr., provided a proper 
relation between the dry and wet-bulb temperatures is maintained. 

The human organism is very susceptible to abrupt changes such as 
might be experienced when passing from outdoors on a cold day into a 
healed room in which the relative humidity is below normal or vice versa. 

A ventilating system, to produce conditions of comfort and health, 
should therefore provide for maintaining a satisfactory relation between 
temperature and humidity. This relation, with a room temperature of 
68 to 70 deg. fahr., generally assumes a relative humidity not belov, JO per 
cent, nor over 60 per cent. Although this assumption is entirely traditional, 
a relation of humidity to temperature may be found between the 1 mits of 
which true comfort will result. 

Investigations from time to time by various engineering organizations 
and civic bodies regarding ventilating methods employed in public buildings, 
and particularly in schools, have disclosed the fact that systems of complete 
hot-blast heating and ventilation have inherent defects. Many former 
advocates of this type of equipment now favor the more modern types of 
"split system." 

7—1 



It has been proven improper from the standpoint of health and com- 
fort to employ a small quantity of highly heated air to replace the heat lost 
by transmission. The air supply should be large in volume and compara- 
tively low in temperature in order to obtain the best ventilating effect. The 
nearer the temperature of the incoming air corresponds to the room temper- 
ature to be maintained, the more nearly is the ideal condition obtained. 

To compensate for the heat losses through wall and glass and other 
exposures, direct radiating surface should be installed. This direct radiat- 
ing surface, if placed under the windows, will also overcome the difficulties 
due to "outside wall and window chill" which, in the hot-blast system of 
heating, has been a source of considerable discomfort. 

The close relation of ventilation and heating makes necessary a discus- 
sion as to the effect of various methods of ventilation upon the design of the 
heating plant. To illustrate these effects, some of the commonest apphca- 
tions of ventilation may be classified as foUows: 

The fireplace. 

Direct-indirect system of heating and ventilation. 

Indirect system of gravity ventilation. 

Ventilating systems for school buildings. 

Ventilating systems of large theatres and auditoriums. 

Ventilation of churches. 

Ventilation of banquet haUs, dining rooms, kitchens, etc. 

Exhaust ventilation of industrial plants. 

Hot-blast systems of heating for industrial plcints. 

The fireplace: The purpose of fireplaces is twofold, first, ornan-iental 
effect, and second, utiUty for warming at times when the heating plant is 
not in operation. Incidentally, also, the flue or chimney of the fireplace 
acts as a vent, the chimney effect or flue draft causing continuous outflow 
of air from the room into the atmosphere. 

This outflow of air from the room through the chimney of the fireplace 
has the tendency of lowering the air temperature and pressure in the room, 
causing a greater infiltration of air from outdoors than would take place 
without the fu-eplace. The additional air find^'ng its way into the room 
tends to lower the temperature, unless compensation is provided in the form 
of sufficient additional radiating surface. 

Direct-indirect system of heating and ventilation: This method of heating 
and ventilation, as described in Chapter 6, has come into quite general use in 
certain sections of the country for ventilating school buildings, public libraries 
and courthouses. 

Indirect system of gravity ventilation: Heating by the indirect system, 
in which the heat is conveyed entirely by air to the space to be heated, 
also provides a fair means of ventilation, but is open to the objection of 
highly heated incoming air. 

The amount of air to be circulated is generaUy stipulated, which re- 
quires knowing the temperature to which the incoming air is to be heated 
so that in cooling from incoming to maintained room temperature enough 
heat units wiU be provided to offset the heat losses tlu-ough windows, wall, 
and other exposures. 

7—2 



In designing heating plants of the indirect type, the total air to be 
circulated must be known within a fair degree of accuracy in order to deter- 
mine the quantity of steam required. 

The indirect method of heating requires from three to four times the 
quantity of steam that would be needed with direct radiation for the same 
warming effect. This indicates the importance of carefully considering 
ventilating problems in connection with heating systems, in order to determine 
proper proportions for boilers, pipes, radiator supply valves, return traps, 
and any other heating system apparatus wliich would be affected by the in- 
creased steam requirement due to the ventilating equipment. 

With the indirect system it is also necessary to provide aspirating 
radiators in the vent flues. 

The method of computing indirect radiating surface for given heating 
effects and requireruents is discussed in Chapter 6. 

Ventilating systems for school buildings: The direct-indirect and the 
indirect systems of heating previously mentioned are frequently used for 
ventilating school houses of the smaller type, but for buildings of larger pro- 
portions mechanical systems of ventilation are generally installed. 

The necessity for healthful and comfortable conditions in school build- 
ings has been the main stimulus for enacting ventilating laws by various 
states and cities. 

Great progress has been made in late years in the design of ventilating 
plants for school buildings. The antiquated hot-blast system of heating 
and ventilation without provision for humidification has been almost 
entirely abandoned and superseded by the modern split-system method of 
ventilating with tempered air, washed and humidified before being dehvered 
into the rooms. Direct radiation is installed for taking care of the heat lost 
through direct exposures of walls, windows, doors, etc. 

Air is generally supplied into the class rooms tlirough registers or dif- 
fusers placed at a level of seven to eight feet above the floor with the vent 
registers near the floor. The most satisfactory arrangement is generally 
obtained when the heat and vent flues are placed in the corridor walls and 
the air is blown towards the windows. The vitiated air is discharged through 
the vent flues into the attic space and passes through ventilators in the roof 
into the atmosphere. 

The cold air intal?.e should preferably be at a point above the roof. 
The intake openings are dampered, and additional air intake openings are 
provided in the attic space, making the re-circulation of air from the building 
possible during the heating-up period in the morning. Delivering the air 
into the rooms at nearly the temperature to be maintained and with auto- 
matic temperature control or modulation supply valves on the direct radia- 
tors, gives ideal conditions as near as obtainable. 

In computing the requirements for direct heating in the ventilated spaces, 
it is only necessary to take into account the heat losses due to exposures. 
Exceptions, however, must be made of rooms which are to be in use after the 
ventilating system is shut down, such as libraries, reading rooms and offices. 

Ventilating systems of school buildings are usually shut down after 
the close of the afternoon session. Any rooms that may be in use after 

7—3 




Fig. 7-1. Sectional elevation through class-rooms of a typical school, showing mechanical ventilating 
equipment and standard method of air supply and venting 

that period should have sufficient direct radiation to take care of the maxi- 
mum requirements without the assistance of the ventilating system. 

The steam required to temper the air needed for the ventilating system 
is generally greatly in excess of that required for the direct system of 
heating. 

Where air washers and humidity control systems are installed, addi- 
tional steam is required to add to the heat in the air, compensating for the 
drop in temperature in passing through the air washer and to supply the 
humidity control apparatus. 

Masonry ducts under floors, if used for the main trunk supply system 
for air distribution, should be so constructed that they can be kept dry at 
all times. The cooling effect of these masonry ducts must be considered in 
tiie design of heating and ventilating plants and during the heating-up period 
sufficient time should be allowed for heating the ducts thoroughly. 

7—4 



The entire heating plant, induding boilers, vacuum pumps, piping 
system and direct radiation, is effected by the method of ventilation. In 
the design of the plant all phases of the application and operation of the 
ventilating system must therefore be known and analyzed to make possible 
a well balanced system. 




Fig. 7-2. 



Arrangement of fresh air diffusers, ventilation registers and direct radiators 
in a modern school room 



Ventilation of theatres and auditoriums: The ventilation of theatres and 
auditoriums presents an entirely different problem from that encountered 
in the ventilation of a building subdivided into a number of comparatively 
small rooms. 

The problem of proper air distribution in large spaces with seating 
capacities numbering into thousands requires special study to provide 
the required quota of fresh air for each occupant. 

The down-flow system of air distribution for large rooms has been found 
to have serious shortcomings because of the difficulty of inducing the air 
flow toward the center portions. The exhaust flues are necessarily in the 
walls and the air currents flow close to them, causing a zone of practically 
no air movement in the center portion. 

The up-flow system of air distribution, admitting the air through open- 
ings in the floor, under the seats, provides a means of distributing the air 
uniformly over the entire area. The spaces under the main floor and under 
floors of balconies are used as plenum chambers into which the fans dis- 

7—5 




7—6 



charge, building up in these chambers a static air pressure and producing 
a uniform outflow of air through each opening. 

It is important that the air outlets shall be proportioned for an air 
velocity through them not exceeding 200 feet per minute. Higher outlet 
velocities are apt to produce objectionable drafts near the floor level. 

With the up-flow system, the openings for the removal of air are placed 
in the ceiling or in the walls near the ceihng. Owing to the difficulty of sup- 
plying a sufficient quantity of warm air in the orchestra pit for proper 
heating, liberal amounts of direct radiation in the pit are usually necessary. 

Ventilating systems for theatres and auditoriums are usually operated 
only during the performances, so that portions of the structure which are in 
use at other times should be heated by direct radiation. 

The quantity of air supplied to theatre auditoriums, on the basis of 
30 cubic feet per minute per occupant, is usually so large that sufficient 
heat is supplied by delivering the air into the space at a temperature a few 
degrees higher than that to be maintained. The temperature regulating 
system should be flexibile enough to automatically reduce the incoming 
air temperature when a large percentage of the seats are occupied and in this 
way prevent excessive temperature rise in the room. 

The modern theatre would not be complete without the installation of 
air washers, humidity-control system, and, for simimer use, a refrigerating 
system for cooling the air. 

The design of heating and ventilating systems for large auditoriums 
presents an interesting problem in engineering. One is so closely affected 
by the other that both should be worked out together so that the results 
obtained will harmonize. 

Ventilation of churches: Ventilation for churches is usually applied only 
to the main auditorium and the Sunday-school room, the balance of the build- 
ing being heated by direct radiation. Most churches are not continuously 
heated, and the warming-up period should on that account receive careful 
consideration by the designer. The ventilating system is generally operated 
during the Sunday services only. 

Whether to use the up-flow system of air distribution or to discharge 
the air into the room through registers in the wall wiU greatly depend on the 
size of the room to be ventilated. In large churches, a combination of both, 
blowing in the air partly through openings in the floors in the aisles, and partly 
through registers in the walls, will give good results. Vent openings are 
usually placed in the walls near the floor and in the ceiling. 

The ventilating system for a church should supply air for ventilation only 
and no attempt should be made to use the fan system for heating. For 
satisfactory results, sufficient direct radiation should be provided to com- 
pensate for all heat losses due to direct exposures and infiltration. Arrange- 
ment for re-circulating the mr before the building is occupied will be found a 
convenience, both from the standpoint of shortening the warming-up period 
and also of effecting a considerable economy in the fuel consumption. 

It is considered good practice to have a separate boiler and piping 
system for that part of the heating and ventilating plant which wiU be in use 
Sundays only, having another boiler to heat the portions of the church in 
use during week davs. 

7—7 



Ventilation of banquet halls, dining rooms, meeting rooms, etc.: In no 
other class of ventilated rooms is the efficiency or inefficiency of the ventilat- 
ing system so noticeable as in banquet halls, dining rooms and meeting 
rooms. Smoke-laden air indicates that the ventilating system is not func- 
tioning properly, while if the air is clear and fresh in spite of smoking by the 
guests, a satisfactory diffusion of air in the room is shown. 

As already pointed out in connection with other ventilating problems, 
the air should be brought in as nearly at room temperature as possible, and 
if heating of the room involves consideration of outside exposures, direct 
radiation should be used. The location and distribution of the exhaust open- 
ings is of prime importance and the exhaust should be accomplished by 
mechanical means. Vent openings should be placed near both floor and 
ceiling, and, if the structural conditions permit, additional vents should be 
provided in the ceihng toward the center of the room. 

Kitchens require a very large air change, which should be accompUshed 
by means of exhaust fans. Ordinances of some cities specify a three-minute 
air change for hotel kitchens, requiring a separate steel vent stack to be 
extended through the roof for this purpose. An exhaust fan, with inlet 
connected to this vent shaft, is usually placed in the penthouse. Above the 




Angle Iron Frame bolted 
to Duct and anchored td 
Brickwork 



^teel Plate Fire Damper 



Jo. 12 U.S.G. Door 
with Angle Iron Frame 



Fig. 7-4. Arrangement of fan, vent stack and safety damper of ventilating equipment for a kitchen 
7—8 ' 



point where the fan inlet connection is made, a tight-fitting damper with 
chain connection is placed in the vent shaft, and the fan discharge is re- 
connected to the vent shaft above this damper. In case the chain connec- 
tion is broken, the damper in the fan intake is closed by gravity, the fan 
inlet is closed and the stack is opened to the atmosphere. The chain con- 
necting the two dampers is provided with a few links of a material having 
low fusing point, so that in case of fire in the stack, the links will melt. 
The damper then disengages, closes the fan intake and permits the stack to 
burn out without damaging the exhaust fan. 

Where kitchens adjoin the dining rooms, the latter can conveniently 
be exhausted through the kitchen. This greatly reduces the inflow of air 
from outdoors into the kitchen and at the same time prevents odors from 
kitchen flowing to dining room. 

Where existing conditions do not permit induction of air from warmed 
spaces to replace that exhaust, the air must necessarily find its way into the 
kitchen from outdoors and provision must be made to prevent a drop 
belcw the desired temperature. This is best accomplished by installing 
direct or indirect rad'ation for heating to the temperature needed. 

Considerable heat is produced by the ranges and steam cooking utensils, 
so that the kitchen may be overloaded with radiation unless complete in- 
formation ie ava lable as to the kitchen equipment to be used. 

Exhaust ventilation of industrial plants: Industries, which in their opera- 
tions produce dust, acid fumes, or in any other way contaminate the air, 
require positive means for removing the dust or fume-laden air from the 
premises. Mechanical systems of exhaust ventilation are used to maintain 
a continuous air change by exhausting the dust-laden air. 

Various types of machines, such as grinders, buffers, and wood-working 
ma h nes, are provided with sheet metal ducts running to the exhaust fans, 
wh ch are usually centrally located, and discharge either into dust-collecting 
chambers or into the atmosphere, depending upon the nature of the dust 
or refuse to be handled. 

The continuous exhausting of air from any space wiU cause a corre- 
spond ng inflow of outdoor air which must be heated to avoid lowering the 
in'^ de temperature. 

If [he ventilated spaces have outside exposures, the air is drawn directly 
frcm OL.ldo:rs, and infiltration takes place uniformly over the entire exposed 
ar a. A sufficient amount of direct heating surface to heat this air to the 
teniperaLure to be maintained must be added to the heating surface required 
for hcat'ng the space without the exhaust system. 

If, however, the vent'lated space has no direct exposure and corinects 
with other rooms so that the air will be drawn from these, the add tional 
radiation must be placed in the rooms from which the air is drawn or indirect 
inleta must be provided. 

Chemical plants requiring the removal of acid fumes must usually 
exhaust large volumes of air from the rooms, and an equivalent quantity 
of a'r must be admitted directly from outdoors. This air is generally ad- 
m tied through special openings in the walls and is drawn through tempering 
coils, so that it enters the room at the temperature to be maintained. In 

7—9 



such ases the (^ontfnt losses can be ehminated from the heat loss calcula- 
tions, and the direct radiation should be sufficient only to compensate 
for the losses through direct exposures and infiltration. However, where 
the exhaust system is in use only at intervals, allowances for heating up 
the contents of the room should be made in figuring the warming-up period. 
Sufficient direct radiation should be added to supply the heat units required 
for this purpose. 

Hot-blast systems of heating for industrial plants: In industrial structures, 
such as large foundries, machine shops, erecting shops and round-houses, 
the hot-blast system of heating, instead of the direct method, is often selected, 
owing to its lower first cost. From the operating standpoint, however, the 
hot-blast system is considerably more expensive than the direct, because of 
the greater amount of steam required for heating by any indirect method. 
This condition is particularly apparent in cases where aU the air is taken 




Fig. 7-5. Axrangement of hot-air ducts of hot-blast system in an industrial plant 



directly from outdoors and after being circulated through the space is dis- 
charged into the atmosphere. 

Where air can be taken from the space to be heated and re-circulated, 
instead of taking it from outdoors, the steam requirements are considerably 
reduced. In either case, the air must be heated at the fan to such a tem- 
perature that in cooling from the air-outlet temperature to that maintained 
inside all heat losses are offset under maximum conditions. 

Only a few general ventilating problems and their direct effect upon 
heating plant design have been mentioned in this chapter, but these show 
the importance of analyzing each ventilating problem thoroughly and 
making all necessary provisions for the ventilating system in heating system 
design. 




Fig. 7-6. Steam-engine-driven fan unit used for heating a storage warehouse 



7—11 



Factors Entering the Design of a Complete Heating and Ventilating Plant 

Ajr Quantities Required for Ventilation : Air quantities in many 
states and municipalities are fixed by legal restrictions which must be carefully 
followed. However, some of the generally accepted standards are mentioned 
in the following paragraphs. 

The type of building and the purpose for which it is to be used are the 
main factors entering into the design of any ventilating system, not only 
as to the type of ventilation which is best adapted to each particular problem, 
but also as to the volume of air required. 

Tables 7-1 and 7-2, list kinds of buildings, together with their air 
requirements. These quantities, with shght variation, have been universally 
adopted. 

Table 7-1. Air Requirements of Various Buildings 

Air Supply 
T- . D ij Cu. Ft. per 

Type of Building Occupant 

per Hr. 

School buildings 1800 

Theatre and assembly halls '. 1500 

Churches 1500 

Prisons 2100 

(Ordinary 2600 

Hospitals! Wounded ^^^^ 

1 Contagion 6000 

Residence 1600 to 2000 

Factories 2000 to 3000 

Table 7-2. Allowable Air Velocities in Various Buildings in Feet per Minute 

Horizontal Vertical 

Ducts Risers Outlets 

Factories 1500 to 2800 

Schools 1000 to 1800 

Hospitals 1000 to 1800 

Theatres 1000 to 1800 

Churches 1000 to 1800 

Sizing of the Ducts: Two methods of estimating duct sizes are in 
common use: 

First, the velocity method, in which the velocity is fixed in the various 
portions of the system, and decreases from the fan outlet to the various 
points of discharge. Tliis method is apphcable in single-duct systems and 
also in public buildings layouts, where certain velocity standards are required 
by law. 

Referring to the duct design in Fig. 7-7, certain volumes and velocities 
are given. To determine the size of ducts at any particular point, the vol- 
ume in cubic feet of air passing that point is divided by the velocity in feet 
at that point, which gives the required area in square feet. 

Determination of the friction in any part of the duct is made by ref- 
erence to the friction chart. Figure 7-8. 

In a single-duct system, the longest duct, or the duct requiring greatest 
pressure, should be designed for certain velocities and the total pressure 

7—12 



900 to 1500 


600 to 1200 


500 to 750 


300 to 500 


500 to 750 


300 to 600 


500 to 750 


300 to 600 


500 to 750 


300 to 600 



/■ ^ I :20ft cii, Fi, 



900 Vel.- 



,5} Sq. Ft. Free Area 4! Sq. Ft, Free Area 



r^l l2D0'Vel. 



j£L 



1200 Ci,. ft. 



~2|Sq. Fl. Free Area 



A 



-I-7 Sq. Ft. Free Area 



crV 



200 Cu. Fl. 

1500 Cu. Ft. X^ I 

1200 Cu. Fl. 
Fig. 7-7. Arrangement of ducts in a trunk-line system. Sized by the velocity method 



~^ 




Fig. 7-8. Arrangement of ducts in a trunk-line system. Sized by the pressure-drop method 

required at plenum chamber determined from the friction chart, Figure 
7-8. All other ducts should then be designed for the same pressure. 

Second — The friction-loss method, in which the duct is proportioned 
for equal friction pressure loss in every foot of run. 

This method of duct sizing necessitates assumption of the velocity 
and volume at the outlets, and is adaptable to trunk-line duct systems such 
as are common in factories. 

Table 7-3 gives an easy and accurate method for sizing ducts. An 
example of its application follows (See Figure 7-9) : 

7—13 



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1,000,000 
800,000 

600,000 
500,000 

400,000 

300,000 

200,000 
150,000 

100,000 

80,000 

60,000 
50,000 

40,000 
30,000 

20,000 -g 
15,000 I 

10,000 I 

8,000 ^ 

6,000 3 
5,000 " 

4,000 

3,000 

2,000 
1,500 

1,000 
800 

000 
500 
401> 
300 

200 
150 

100 



Friction in Inches Water Gauge per 100 Feet " 

Fig. 7-9. Chart for detenninins pressure loss in ducts 

Assuming a 1000 cu. ft. discharge from each outlet at 1000 ft. velocity 
per min. the area of the outlet is one (1) sq. ft. or say 14 inches in diameter. 

Referring to Table 7-3, a 14-in. pipe is equivalent to 737 1-inch pipes 
and two 14-in. pipes are equivalent to 1474 1-in. pipes. Also, 1474 1-inch 
pipes are equivalent to approximately a 19-in. pipe, and so on. To deter- 

7—14 



Talile 7-3. Comparison of the Air-carrying Capacity of Various Sizes of Pipes 

with That of a 1-in. Pipe of Same Length and Equal Friction 

Pressure Loss 

For Example — With an equal pressure loss and equal length, a 4-in. diameter pipe will carry the same 
volume of air as thirty-two 1-in. pipes. 



Diam. 


1" Pipes 


Diam. 


1" Pipes 


Diam. 


1" Pipes 


Diam. 


1 " Pipes 


Diam. 


1" Pipes 


1 


1 


21 


1985 


41 


10565 


61 


28850 


81 


59122 


2 


5 


22 


2250 


42 


11300 


62 


30200 


82 


60831 


3 


16 


23 


2525 


43 


12030 


63 


31350 


83 


62510 


4 


32 


24 


2800 


44 


12621 


64 


32500 


84 


64249 


5 


56 


25 


3060 


45 


13400 


65 


33975 


85 


66396 


6 


88 


26 


3425 


46 


14100 


66 


35300 


86 


68512 


7 


129 


27 


3738 


47 


15000 


67 


36600 


87 


70687 


8 


180 


28 


4100 


48 


15850 


68 


38000 


88 


72833 


9 


244 


29 


4440 


49 


16610 


69 


39275 


89 


74979 


10 


317 


30 


4898 


50 


17600 '' 


70 


40250 


90 


77125 


11 


402 


31 


5312 


51 


18275 


71 


41995 


91 


79271 


12 


501 


32 


5631 


52 


19335 


72 


43740 


92 


. 81416 


13 


613 


33 


6154 


53 


20000 


73 


45449 


93 


83562 


14 


737 


34 


6675 


54 


21500 


74 


471.58 


94 


85708 


15 


876 


35 


7075 


55 


22300 


75 


48887 


95 


87834 


16 


1026 


36 


7735 


56 


23450 


76 


50576 


96 


89999 


17 


1197 


37 


8265 


57 


24500 


77 


52285 






18 


1375 


38 


8715 


58 


25600 


78 


53995 






19 


1580 


39 


9350 


59 


26700 


79 


55704 






20 


1775 


40 


10060 


60 


27700 


80 


57413 







Table 7-4. Resistance of 90-degree Elbows 



Radius of throat 

of elbow in 

diameters of 

pipe 



Number of diameters 

of straight pipe 

offering equivalent 

resistance 



Radius of throat 

of elbow in 

diameters of 

pipe 



Number of diameters 

of straight pipe 

offering equivalent 

resistance 



%■ 
1 . 

VA- 
2 . 



67.0 


21^ 


30.0 


3 


16.0 


SH 


10.0 


4 


7.5 


4^ 


6.0 


5 


5.0 


5y2 


4.3 





4.5 
4.8 



mine the velocity at any point, the volume at that point is divided by the 
area in sq. ft. To determine the friction in any portion of the duct reference 
is made to friction chart Fig. 7-9. 

CA.LCULATION OF RESISTANCE OR PRESSURE: It is not the intention 
to go into the many complex formula entering into the loss of pressure 
in ducts but rather to arrange some easily workable method. 

The friction chart, Figure 7-9, which is worked out from accepted 
pressure loss formula, provides a quick, accurate method for determining 
pressure loss. 

Example: Assume that 30,000 cu. ft. of air per minute is passed through 
a duct 40 inches in diameter and 50 feet long. From the 30,000 cu. ft. divi- 
sion at the right of chart, trace horizontally to intersection with the line rep- 
resenting 40 dia. pipe. Perpendicularly down from this point the friction 
in inches of water per hundred feet of pipe is given — in tliis case .54 inches. 

For 50 ft. the friction will be 50% of .54 or .27 in. of water. Friction 
in inches of water multiplied by 0.58 gives friction in ounces. 

The resistance is expressed as that of the number of diameters of straight 

7—1.5 



w 








Ratio of long side of rectanoular duct to diameter of Round P 


pe 


Iravinfl 


same 


resistance for 


same cl 


. ft. per 


min. 


A 


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u 




































































































































































































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L. 

















































































0.7 0.8 0.9 1.0 l.X 1.2 1.3 1.4 1.5 1.6 1.7 1.8 



2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 



Fig. 7-10. Curve for determining the diameters of romid pipes having the same friction loss for 
same capacity as rectangular ducts of various dimensions 



pipe of same diameter as the elbow, and is given for elbows having different 
radii of throat, also expressed in diameters of pipe. For instance, a 90- 
deg. elbow of 24-inch pipe, having a radius of throat equal to 1 diameter, 
that is 24 inches, offers the same resistance to the flow of air as 10 diameters 
of straight pipe or 20 feet of straight pipe. 

To the resistance of the duct system should be added the resistance 
through tempering and reheating coils, also air washers, plus a small factor of 
safety, thereby determining the total pressure against which the fan must 
deliver the specified volume of air. 

Where each branch duct leaves the trunk hne, there should be provided 
a volume damper with trunnion, quadrant and locking device, for balancing 
up the system. 

Figure 7-10 is a curve for determining diameter of round pipe having 
same friction for Scime capacity as rectangulcir ducts of varying dimensions. 

Selecting the Apparatus 

Sizes and arrangement of fans: For fan performances and capacities, 
reference should be made to the tables issued by the manufacturers of such 
equipment. 

7—16 



Table 7-5. Ciibic Feet of Air One B.t.u. Will Raise One Degree Fahr. at 
Different Temperatures 

Specific heat of air .2375. At zero one cubic foot of air weighs .0864 
lb. and JJfe = 11.574 cu. ft. ^iS^ = 48.77 cu. ft. raised one degree by 1 



.0864 



.2375 



B.t.u. 



Table constructed from this formula, small fractional decimals omitted 



Temp. 


Weight 




Cu. ft. 1 


Temp. 


Weight 




Cu. ft. 1 


Temp. 


Weight 




Cu. ft. 1 


air deg. 


of I 


Cu. ft. 


B.t.u. will 


air deg. 


of 1 


Cu. ft. 


B.t.u. will 


air deg. 


of 1 


Cu. ft. 


B.t.u. will 


fahr. 


cu. ft. 


in 1 lb. 


raise 1 
deg. fahr. 


fahr. 


cu. ft. 


in 1 lb. 


raise 1 
deg. fahr. 


fahr. 


cu. ft. 


in 1 lb. 


raise 1 
deg. fahr. 





.0864 


11.58 


48.77 


72 


.0747 


13.39 


56.40 


152 


. 0649 


15.40 


64.90 


12 


.0842 


11.87 


50.00 


82 


.0733 


13.64 


57.40 


162 


. 0638 


15.65 


66.00 


22 


.0824 


12.14 


51.00 


92 


.0720 


13.90 


58.60 


172 


.0628 


15.90 


67.00 


32 


.0807 


12. 10 


52.20 


102 


.0707 


14.14 


59.20 


182 


.0618 


16.17 


68.00 


42 


.0791 


12.61 


53.10 


112 


.0694 


14.40 


60.60 


192 


.0609 


16.42 


69.10 


52 


.0776 


12.88 


54.10 


122 


.0682 


14.65 


61.60 


202 


.0600 


16.67 


70.10 


62 


.0761 


13.13 


55.20 


132 


.0671 


14.90 


62.80 


212 


.0591 


16.92 


71.30 


70 


. 07.50 


13.34 


56.30 


142 


.0660 


15.15 


63.80 











Heaters: To select a heater for any set of conditions it is necessary to 
know the volume of air to be handled, its initial temperature, and the 
temperature to which it must be raised. 

Two methods for determining the above quantities are available 
where the building is heated as well as ventilated by the air. One applies 
where a definite air change is desired or where ventilation must be provided 
for a given number of people. 

Example: Assume a building requiring 18,000 cu. ft. per min. measured 

at 70 deg. fahr. with a total of 860,000 B. t. u. loss through exposed glass, walls, 

rp, B.t.u. Loss ,.^ . 

etc. inen -=q — -^ -. — — — , = diiiusion 

Cu. It. per mm. X .2375 X .075 X 60 



860,000 



= 45 deg. fahr. 



18000 X .2375 X .075 X 60 
45 deg. diffusion + 10 deg. duct loss + 70 deg. desired room temperature = 
125 deg. final temperature at coils. In this calculation .2375 is the specific 
heat of air and is constant and .075 is the weight of one cubic foot of air 
at the room temperature of 70 deg. (See Table 7-5). 

The other method is to decide on the final temperature to be used with 
some fixed entering temperature. 

Example: Suppose the heat loss through exposed walls, glass, etc., is 
1,204,500 B.t.u. Assume a final temperature at the heater of 135 deg. 
fahr. and a loss of 10 deg. in the ducts. The temperature at the duct 
outlets will then be 125 deg. fahr. The room temperature desired is 65 deg. 
and the outside temperature is deg. 

The difference in the temperature between the duct outlets and the 
room temperature is available for heating. 

p . . ^ B.t.u. per hr. _ 1,204,500 

P^^ ™"" 60 X 60 X .2375 x .068 60 x 60 x .2375 x .068 
20,720 cu. ft. per min. required, in which .2375 is specific heat of air and is 
constant and .068 is weight of one cu. ft. of air at 65 deg. (See Table 7-5). 

7—17 



Either of the above formulas can be used on spht systems where a 
portion of the losses through walls, glass, etc., are taken care of by direct radia- 
tion, and the balance by the incoming air. In the spht system where all 
heat loss through walls, glass, etc., is taken care of by direct radiation, the final 
temperature of the air is of course, the same as the room temperature de- 
sired. However, in choosing the heater, allowance should be made for some 
temperature drop in the ducts (usually 10 to 20 degrees). 

After we have determined the volume and final temperature of the air 
the size of heater can readily be chosen from tables furnished by manufac- 
turers. 

Table 7-6. B.t.u. Required for Heating Air 

This table specifies the quantity of heat in British thermal units required to raise one cubic foot of 
air through any given temperature interval. 

Temperature of Air in Room, deg. fahr. 



External 
Temp. 


40° 


50° 


60° 


70° 


80° 


90° 


100° 


110° 


120° 


130° 


-40° 


1.802 


2.027 


2.252 


2.479 


2.703 


2.928 


3.154 


3.379 


3.604 


3.829 


-30' 


1.510 


1.760 


1 980 


2.200 


2.420 


2.640 


2.860 


3.080 


3.300 


3. 520 


-20° 


1.290 


1.505 


1.720 


1.935 


2.150 


2.365 


2.580 


2.795 


3.010 


3.225 


-10° ~ 


1.051 


1.262 


1 . 473 


1.684 


1.892 


2.102 


2.311 


2.522 


2.7.32 


2.943 


0° 


0.822 


1 . 028 


1.234 


1.439 


1.645 


1.851 


2 0.56 


2.262 


2.467 


2.673 


10° 


0.601 


0.805 


1.007 


1.208 


1 . 409 


1.611 


1.812 


2.013 


2.215 


2.416 


2')° 


0.393 


>90 


0.737 


0.984 


1.181 


1.378 


1.575 


1.771 


1.968 


2.165 


30° 


0.192 


0.385 


0.578 


0.770 


0.963 


1.1.55 


1.345 


1.540 


1.733 


1.925 


40= 


0.000 


0.188 


0.376 


0.564 


0.752 


0.940 


1.128 


1.316 


1.504 


1.692 


50° 


0.000 


0.000 


0.184 


0.367 


0.551 


0.735 


0.918 


1.102 


1.286 


1.470 


60° 


0.000 


0.000 


0.000 


0.179 


0.359 


0.538 


0.718 


0.897 


1.077 


1.256 


70° 


000 


0.000 


0.000 


0.000 


0.175 


0.350 


0.525 


0.700 


0.875 


1.049 



Above table from F. Schumann's Manual of Heating and-VentUation. 

Boiler Horsepower required: To determine the boiler horsepower re- 
quired for air heating, the following formula can be used : 

Cu. ft. per min. X60XA tu+ i, 

i- =- — — i — = Lb. steam per hour. 

r> 

in which A = B.t.u. required for heating one cu. ft. of air from initial to 

final temperature (See Table 7-6). 

B = latent heat of steam — 

Lb. steam per hr. t? -i i 

J^ = Boiler horsepower 

From the manufacturers' tables the condensation rates per square foot 
of surface are given for various velocities and temperatures, and it is well 
to check up the above formula from these given factors. 



7—18* 



CHAPTER VIII 



Proportioning of Chimneys 

NO problem in the heating- of buildings presents greater elements of 
uncertainty than that of properly proportioning the chimney. 
In larger installations, such as isolated plants for the production 
of power, light and heat, the conditions may usually be very accurately 
determined in advance. By use of the formula given hereafter, proper 
results follow in almost every case. 

A. Chimneys for House-Heating Boilers 

In small plants, and particularly residence heating, it is not practicable 
to mEike such accurate advance determinations of all the conditions. Usually 
the chimney is built into the wall, thereby requiring that its cross-section 
must be proportioned to the width of brick. Chimneys so built are usually 
either smoothly mortared on the inside or lined with thin tile of rectangular 
or circular cross-section. The latter 



•//,///////M/77/a 




gives such freedom from friction and 
eddy currents and lessened surface for 
loss of heat in the gases that a round 
chimney hning will frequently give 
fully as good results as would be ob- 
tained in the square of brick-work in 
which it is enclosed. 

The inclination to cut down cross- 
sectional area to save cost and space 
in the portion of building through 
which the chimney passes should be 
discouraged as false economy. Once the chimney is built into the structure, 
increase of area is practically impossible, and a chimney that is too small 
remains a source of discomfort and waste during the entire life of the struc- 
ture. Little is saved in building an 8}^ inch by 13 inch flue as compared 
with a 13 inch by 18 inch flue, the latter having more than twice the area and 
more than twice the capacity, while the bricks per course are as 9 is to 7. 
See Figure 8-2. 



Fig. 8-1. 



Cross-sections through 
chimneys. 



typical house 







|-» ll?-8- 


V 








1 
f 

1 






-r:-..: ■ 




t 




Inside Area equals 
80 sq.ins. 


7 




















r 


,, 












Fig. 8-2. 



Fig. 8-3. 



To get the greatest effectiveness, a definite amount of draft must be 
available. The actual amount required varies widely for different types of 
commercial cast-iron boilers, and, unfortunately, it is not always possible 
to know in advance which make of these boilers will be selected or may 
later be installed. It is, therefore, preferable to provide for excessive draft 
which may be controlled by damper, rather than to risk insufficient draft, 
the remedying of which is almost hopeless. 

The curves in Figure 8-3 on page 8-1 indicate the probable capacity of 
chimneys of differing sizes and forms and various heights necessary to produce 
the proper draft for the average cast-iron heating boiler capable of generating 
steam at the given hourly rate. 

It must, however, be borne in mind that the location of the building in 
relation to topography and surrounding structures may render a chimney 
absolutely inefficient, while another similar in every respect of height and 
cross-section, used for similar boiler and fuel, but favorably located, will be 
able to produce a superabundance of draft; also that the resistance due to 
thickness of coal bed, character and quality of fuel as well as resistance be- 
tween the combustion chamber and chimney vary in different makes of 
boilers having similar ratings, and that these resistances form a large part 
of the total head for which chimneys are required. 

Table 8-1. Dimensions of Flue Linings 























AS 


MANUFACTURED 


BY 




















The Delaware Clay Products Co 




W. S. Dickey Clay Mfg. Co. 


Robinson Clay Products Co. 


Pittsburgh, Penna. 






Kansas City, Mo. 


Akron, Ohio 




Rectangular 
and Square 


Circular 


Rectangular 
and Square 


Circular 


Rectangular 
and Square 


Circular 


Sq. 










Sq. 






Sq. 










Sq. 






Sq. 










Sq. 






In. 










Tn. 






In. 










In. 






In. 










In. 






Free 


A 


B 





T) 


Free 


E 


F 


Free 


A 


B 


C 


D 


Free 


E 


F 


Free 


A 


B 


c 


u 


Free 


F. 


F 


Area 


3^ 




iV, 


8V, 


Area 
28 






Area 


3H 






8H 


Area 






Area 


3!4 








Area 

28 


6 




23 


7¥ 


6 


TH 


29 


■7% 


iVi. 




23 


7 


434 


&% 


714 


M 


3'/, 


IIV, 


4Vo 


13 


38 


V 


8»/, 


61 


TH 


7-h} 


sv. 


8 14 








36 


3tV 


11-H 


434 


1314 


38 


7 


8H 


47 


2'/, 


IfiH 


4Vo 


IS 


51) 


8 


9J/, 


46 


■i% 


1214 


4H 


13 








60 


3'/, 


15H 


4y, 


IV 


50 


S 


9 


39 


6)4 


6M 


7K 


7K 


64 


9 


lOi'V 


92 


7% 


12H 


SH 


13 








47 


4>-2 


10^ 


6 


12 


64 


9 


lOH 


52 


7A 


7A 


8^ 


8v; 


78 


10 


11?< 


145 


12A 


12A 


13 


13 








33 


534 


5»4 


7!4 


7¥ 


78 


10 


12 


SO 


fi+f 


11,V 


SU 


13 


113 


12 


14 


127 


VVb 


Ki-v, 


SV4 


17 V, 


125 


12 V, 


14^4 


52.5 


V'4 


VH 


Si/, 


SH 


113 


12 


14 


110 


C^^ 


Hi '4 


su 


IS 


17fi 


15 


17M 


202 


12H 


16'^, 


13 


17 Vo 








SO 


B'/s 


IIH 


SVo 


13 


176 


15 


17 V« 


129 


UH 


115^ 


13 


13 


254 


IS 


2U1/2 


270 


16,^ 


16 A 


17K 


17^2 








104 


BJ4 


16 


S^2 


IS 


2,54 


18 


■M/i 


18S 


11 K 


1R3^ 


13 


18 


314 


20 


22=4 












291 


19i.!i' 


2114 


127 


llVi 


im 


13 


13 


314 


20 


23 


25H 


1R 


1H 


IH 


IX 


38(1 


22 


2fli,( 


















169 


lO^M 


ibH 


13 


18 


346 


21 














452 


24 


271.1 












499 


25 A 


27^2 


■240 


15^2 


i5;'2 


IS 


18 


380 
452 

572 
707 
855 
1018 


22 
24 

27 
30 
33 
36 


27 
35 



Note. All dimensions are in inches and subject to slight variations. 



8—2 



1400 5600 



1300 5200 



1200 4800 




'23'\ 27"floaoh 6Mck 
20"x 24"Flue Linlnn 



'23 X 23 Rough Brick 
20"x20"Flue Linlno 
20"dia. '■ 



20 X 20' Rough Brick 
18"dia. Flue Lining 



18"x 22"Rough Briek 
16"x20"Flue Lining 



18"x 18' Rough Brick 
16"x I6"Flue Lining 



15 dia. Flue Lining 



13 x22"flougb Brick 
12"x 20" Flue Lining 



13 X 18 Rough Brick 
12'x 16 Flue Lining 

1 3"x 1 3"Rough Brick 
12x12 Flue Lining 
12"dia. ■■ 
lU'x l6J"Flue Lining 

lll'x lll"Flue Lining 



ylO dia. Flue Lining 
,/8^'|x 17i" Rough Brick 

7i"x 16|"Flue Lining 

.^65 X 16i Flue Lining 

i"x 13"Rough Brick 

7S"x 12 J" Flue Lining 
'x 11 -j^ Flue Lining 

8J"x 8J"Rouoh Brick 
V7S"x 7«"Flue Lining 
,l8"dia. Flue Lining 

7-^' X 7t^" Flue Lining 



20 30 40 50 60 70 

Feet in Height between Combustion Chamber and Top of Chimney 



Fi?. 8-3 — Probable capacities of chimneys of different forms, sizes and heights to produce 
proper draft for average cast-iron boiler using anthracite coal. 



8— 2a 



B Chimneys and Draft for Power Boilers* 

The height and diameter of a properly designed chimney depend upon 
the amount of fuel to be burned, the design of the flue, with its arrange- 
ment relative to the boiler or boilers, and the altitude of the plant above sea 
level. There are so many factors involved that as yet there has been pro- 
duced no formula which is satisfactory in taking them all into consideration 
and the methods used for determining stack sizes are largely empirical. In 
this chapter a method sufficiently comprehensive and accurate to cover all 
practical cases will be developed and illustrated. 

Draft is the difference in pressure available for producing a flow of the 
gases. If the gases within a stack be heated, each cubic foot will expand, 
and the weight of the ex])anded gas per cubic foot will be less than that of a 
cubic foot of the cold air outside the chimney. Therefore, the unit pressure 
at the stack base due to the weight of the column of heated gas will be less 
than that due to a column of cold air. This difference in pressure, likfe the 
diff'erence in head of water, will cause a flow of the gases into the base of the 
stack. In its passage to the stack the cold air must pass through the furnace 
or furnaces of the boilers connected to it, and it in turn becomes heated. 
This newly heated gas will also rise in the stack and the action will be con- 
tinuous. 

The intensity of the draft, or difference in pressure, is usually measured 
in inches of water. Assuming an atmospheric temperature of 62 deg. 
falu'. and the temperature of the gases in the chimney as .500 deg. fahr., 
and, neglecting for the moment the difference in density between the chim- 
ney gases and the air, the difference between the weights of the external air 
and the internal flue gases per cubic foot is .0347 pounds, obtained as follows : 
Weight of a cubic foot of air at 62 deg. fahr. = .0761 pound 
Weight of a cubic foot of air at 500 deg. fahr. = .0414 pound 

Difference = .0347 pound 
Therefore, a chimney 100 feet high, assumed for the purpose of illustration 
to be suspended in the air, would have a pressure exerted on each square 
foot of its cross-sectional area at its base of .0347 x 100 = 3.47 pounds. As 
a cubic foot of water at 62 deg. fahr. weighs 62.32 pounds, an inch of water 
would exert a pressure of 62.32-^12 = 5.193 pounds per square foot. The 
100-foot stack would, therefore, under the above temperature conditions, 
show a draft of 3.47^5.193 or approximately 0.67 inches of water. 

The method best suited for determining the proper proportion of stacks 
and flues is dependent upon the principle that if the cross-sectional area 
of the stack is sufficiently large for the volume of gases to be handled, the 
intensity of the draft will depend directly upon the height; therefore, the 
method of procedure is as follows: 

(1) Select a stack of such height as will produce the draft required by 
the particular character of the fuel and the amount to be burned per square 
foot of grate surface. 

(2) Determine the cross-sectional area necessary to handle the gases 
without undue frictional losses. 

* Reprinted from Slenni by iicrinission of Bibcock iS; Wilcox Co. 
8—3 



The application of these rules follows: 

Draft Formula — The force or intensity of the draft, not allowing for 
the difference in the density of the air and of the flue gases, is given by the 
formula: 

D = 0.52 HxP^i — 1) (Formula 8-1) 

in which • 

D = draft produced, measured in inches of water, 

H = height of top of stack above grate bars in feet, 

P = atmospheric pressure in pounds per square inch, 

T = absolute atmospheric temperatm-e, 

Ti = absolute temperature of stack gases. 

In this formula no account is taken of the density of the flue gases, it 
being assumed that it is the same as that of air. Any error arising from this 
assumption is negligible in practice, as a factor of correction is apphed in 
using the formula to cover the difference between the theoretical figiu'es and 
those corresponding to actual operating conditions. 

The force of draft at sea level (which corresponds to an atmospheric pres- 
sure of 14.7 pounds per square inch) produced by a chimney 100 feet high 
with the temperature of the air at 60 degrees falir. and that of the flue gases 
at 500 degrees falir. is, 

D = 0.52 X 100 X 14.7 ( -L _ 1 ) = 0.67 
\521 961/ 

Under the same temperature conditions this chimney at an atmospheric 
pressure of 10 pounds per square inch (which corresponds to an altitude of 
about 10,000 feet above sea level) would produce a draft of, 

D = 0.52 X 100 X 10. (^4j - ^) = 0.45 

For use in applying this formula it is convenient to tabulate values of 
the product 



0.52 X 14.7 



[ T tJ 



which we will call K, for various values of Ti. With these values calculated 
for assumed atmospheric temperature and pressure, Formula 8-1 becomes 

D = K H. (Formula 8-2.) 

For average conditions the atmospheric pressure may be considered 
14.7 pounds per square inch, and the temperature 60 deg. fahr. For these 
values and various stack temperatures K becomes: 

Temperalure Slack Gases Constant K 

750 • 0084 

700 0081 

650 0078 

600 0075 

550 0071 

500 ■ 0067 

450 0063 

400 : :0058 . 

350 0053 

O — 4 



Draft Losses — The intensity of the draft as determined by the above 
formula is theoretical and can never be observed with a draft gauge or any 
recording device. However, if the ashpit doors of the boiler are closed and 
there is no perceptible leakage of air tlirough the boiler setting or flue, the 
draft measured at the stack base will be approximately the same as the 
theoretical draft. The difference existing at other times represents the pres- 
sure necessary to force the gases through the stack against their own inertia 
and the friction against the sides. This difference will increase with the 
velocity of the gases. With the ashpit doors closed the volume of gases 
passing to the stack are a minimum and the maximum force of draft will be 
shown by a gauge. 

As draft measurements are taken along the path of the gases, the read- 
ings grow less as the points at which they are taken are farther from the 
stack, until in the boiler ashpit, with the ashpit doors open for freely admit- 
ting the air, there is little or no perceptible rise in the water of the gauge. 
The breecliing, the boiler damper, the baffles and the tubes, and the coal on 
the grates all retard the passage of the gases, and the draft from the chimney 
is required to overcome the resistance offered by the various factors. The 
draft at the rear of the boiler setting where connection is made to the stack 
or flue may be 0.5 inch, while in the furnace directly over the fire it may 
not be over, say, 0.15 inch, the difference being the draft required to overcome 
the resistance offered in forcing .the gases through the tubes and around 
the baffling. 

One of the most important factors to be considered in designing a stack 
is the pressure required to force the air for combustion through the bed of 
fuel on the grates. This pressure will vary with the nature of the fuel 
used, and in many instances will be a large percentage of the tota draft. 
In the case of natural draft, its measure is found directly by noting the 
draft in the furnace, for with properly designed ashpit doors it is evident 
that the pressure under the grates will not differ sensibly from atmosphere 
pressure. 

Loss IN Stack — The difference between the theoretical draft as de- 
termined by Formula 8-1 and the amount lost by friction in the stack 
proper is the available draft, or that which the draft gauge indicates when 
connected to the base of the stack. The sum of the losses of draft in the 
flue, boiler and furnace must be equivalent to the avaflable draft, and as 
these quantities can be determined from record of experiments, the problem 
of designing a stack becomes one of proportioning it to produce a certain 
available draft. 

The loss in the stack due to friction of the gases can be calculated from 
the f oUowing formula : 

AD =- ^P^ (Formula 8-3) 

in which 

A D = draft loss in inches, of water, 

W = weight of gas in pounds passing per second, 

C = perimeter of stack in feet, 

H = height of stack in feet, 

8—5 



/ = a constant with the following values at sea level : 

.0015 for steel stacks, temperature of gases 600 deg. fahr. 

.0011 for steel stacks, temperature of gases 350 deg. falir. 

.0020 for brick or brick-lined stacks, temperature of gases 600 deg. 

falir. 

.0015 for brick or brick-Hned stacks, temperature of gases 350 deg. 

fahr. 
A = area of stack in square feet. 

This formula can also be used for calculating the frictional losses for 
flues, in which case, C = the perimeter of the flue in feet, H = the length of 
the flue in feet, the other values being the same as for stacks. 

The available draft is equal to the difference between the theoretical 
draft from Formula 8-2 and the loss from Formula 8-3, hence: 

fW'CH 



d^ = available draft = KH 



(Formula 8-4) 



Table 8-0. Available Draft 



Calculated for 100 ft. stack of different diameters assuming stack temperature of 500° F. 
gas per H. P. For other heights of stack multiply draft by height H- 100 


and 100 lbs 


• of 


Horse 


DIAMETER OF STACK IN INCHES 


Horse 
Power 


DIA. STACK IN INCHES 


Power 


36 


42 


48 


54 


60 


66 


72 


78 


84 


90 


96 


102 


108 


114 


120 


90 


96 


102 


108 


114 


120 


132 


144 


100 
200 
300 


64 
.55 
.41 


.62 
.55 


.61 


























2600 
2700 
2800 


.47 
.45 
.44 


.53 
.52 
.50 


.56 
.55 
.55 


.59 
.58 
.58 


.61 
.60 
.60 


.62 
.62 
.61 


.64 
.64 
. 61 


.65 
.65 
.65 


400 
500 
600 


.21 


.46 
.34 
.19 


.56 
.50 
.42 


.61 
.51 
.53 


.61 
.59 






















2900 
3000 
3100 


.42 
.40 
.38 


.49 
.48 

.47 


..54 
.53 
.52 


..57 
.56 
.56 


.59 
.59 
.58 


.61 
.61 

.60 


.63 
.63 
.63 


.65 
.64 
.64 


700 
800 
900 






.34 
.23 


.48 
.43 
.36 


.56 
.52 
.49 


.60 
.58 
.56 


.63 
.61 
.60 


.63 
.62 


.64 














3200 
3300 
3400 




.45 
.44 
.42 


.51 
.50 
.49 


.55 
.54 
.53 


.58 
.57 
.56 


.60 
.59 
.59 


.63 
.62 
.62 


.64 
.64 
.64 


1000 
1100 
1200 








.29 


.45 
.40 
.35 


.53 
.50 

.47 


.58 
.56 
.54 


.61 
.60 
.58 


.63 
.62 
.61 


.64 
.63 
.63 


64 
.64 


.65 








3500 
3600 
3700 




.40 


.48 

.47 
.45 


.52 
.52 
.51 


.56 
.55 
.55 


.58 
.58 

.57 


.62 
.61 
.61 


.64 
,63 
.63 


1300 
1400 
1500 










.29 


.44 
.40 
.36 


.52 
.49 

.47 


.57 
.55 
.53 


.60 
.59 
.58 


.62 
.61 
.60 


.63 
.63 
.62 


.64 
.64 
.63 


.65 
.65 
.64 


.65 
.65 


.65 


3800 
3900 
4000 






.44 
.43 
.42 


.50 
.49 
.48 


.54 
.53 
.52 


.57 
.56 
.56 


.61 
.60 
.60 


.63 
.63 
.62 


1600 
1700 
1800 












.31 


.43 
.41 
.37 


.52 
.50 
.47 


.56 
.55 
.54 


.59 
.58 

..57 


.62 
.61 
.60 


.63 
.62 
.62 


. 61 
.64 
.63 


.65 
.64 
.64 


.65 
.65 
.65 


4100 
4200 
4300 






.40 
.39 


.47 
.46 
.45 


..52 
.51 
.50 


.55 
.55 
.54 


.60 
.59 
.59 


.62 
.62 
.62 


1900 
2000 
2100 














.34 


.45 
.43 
.40 


.52 
.50 
.49 


.56 
.55 
.54 


.59 
.59 
.58 


.61 
.61 
.60 


.63 
.62 
.62 


.64 
.63 
.63 


.64 
.64 
.64 


4400 
4500 
4600 








.44 
.43 
.42 


.49 
.49 
.48 


.53 
.53 

.52 


.59 
.58 
.58 


.62 
.61 
.61 


2200 
2300 
2400 
















.38 
.35 
.32 


.47 
.45 
.43 


.53 
.52 
.50 


.57 
.56 
.55 


.59 
.59 
.58 


.61 
.61 
.60 


.62 
.62 
.62 


.64 
.63 
.63 


4700 
4800 
4900 








.41 
.40 


.47 
.46 
.45 


.51 
.51 
.50 


.57 
.57 
.57 


.61 
.60 
.60 


2500 


















.41 


.49 


..54 


..57 


.60 


.61 


.63 


5000 










.44 


.49 


.56 


.60 



For Other Stack Temp. Add or Deduct Before Multiplying by 



Heielu 



For 750° Fahr. 

-A.dd . 17 In. 
For 700° Fahr. 

Add . 14 In. 



For 650° Fahr. 

Add . 11 In. 
For 600° Fahr. 

Add . 08 In. 



For 550° Fahr. 

Add .04 In. 
For 450° Fahr. 

Deduct .04 In 



For 400° Fahr. 

Daduct . 09 In. 
For 350° Fahr. 

Deduct . 14 In. 



8—6 



Table 8-1 gives the available draft in inches that a stack 100 feet high 
will produce when serving dififerent horse powers of boilers with the methods 
of calculation for other heights. 

Height and Diameter of Stacks — From Formula 8-4, it becomes 
evident that a stack of certain diameter, if it be increased in height, wiU 
produce the same available draft as one of larger diameter, the additioned 
height being required to overcome the added frictional loss. It follows that 
among the various stacks that would meet the requirements of a particular 
case there must be one which can be constructed more cheaply than the 
others. It has been determined from the relation of the cost of stacks to 
their diameters and heights, in connection with the formula for available 
draft, that the minimum cost stack has a diameter dependent solely upon 
the horse power of the boilers it serves, and a height proportional to the 
available draft required. 

Assuming 120 pounds of flue gas per hour for each boiler horse power, 
which provides for ordinary overloads and the use of poor coal, the method 
above stated gives: 

For an unlined steel stack —diameter in inches = 4.68 h.p. f . (For- 
mula 8-5.) 

For a stack lined with masonry — diameter in inches = 4.92 h.p. f . 
(Formula 8-6.) 

In both of these formulae h.p. = the rated horse power of the boiler. 

From this formula the curve, Figure 8-4, has been calculated and from 
it the stack diameter for any boiler horse power can be selected. 



ISU 






































J 


■ 


120 
110 


































^ 






































^ 
































^ 


^ 
















90 
80 


















^ 




































^ 


^ 




































y 






























70 










^ 






































^ 


^ 
































60 








/^ 






































/ 




































."iO 






/ 






































/ 




• 


































40 




/ 






































/ 








































no 


/ 








































/ 








































20 
10 


/ 








































( 

















































































200 -too GOO 800 1000 1200 1400 1600 1800 2000 2200 2400 2000 2800 3000 3200 3400 3600 3S00 4000 

Horsepower of Boilers 

Fis. 8-4 Diameter of Stacks and Horse Power thej' will Serve 
Compnted from Fonmila (8-5). For brick or brick-lined stacks Increase the diameter 6 per cent. 



8—7 



For stoker practice where a large stack serves a number of boilers, the 
area is usually made about one-third more than the above rules call for, 
which allows for leakage of air tlirough the setting of any idle boilers, ir- 
regularities in operating conditions, etc. 

Stacks with diameters determined as above will give an available 
draft which bears a constant ratio of the theoretical draft, and allowing for 
the cooling of the gases in their passage upward through the stack, this 
ratio is 8. Using this factor in Formula 8-2, and transposing, the height of 
the chimney becomes, 

II = -^ (Formula 8-7) 

Where H = height of stack in feet above the level of the grates, 

d' = available draft required, 

Iv = constant as in formula. 

Losses in Flues — The loss of draft in straight flues due to friction and 
inertia can be calculated approximately from Formula 8-3, which was given 
for loss in stacks. It is to be borne in mind that C in this formula is the 
actual perimeter of the flue and is least, relative to the cross-sectional area, 
when the section is a circle, is greater for a square section, and greatest for a 
rectangular section. The retarding efi^ect of a square flue is 12 per cent 
greater than that of a circular flue of the same area and that of a rectangular 
with sides as 1 and 13/2? 15 per cent greater. The greater resistance of the 
more or less uneven brick or concrete flue is provided for in the value of the 
constants given for Formula 8-3. Both steel and brick flues should be short 
and should have as near a circular or square cross-section as possible. 
Abrupt turns are to be avoided, but as long easy sweeps require valuable 
space, it is often desirable to increase the height of the stack rather than to 
take up added space in the boiler room. Short right-angle turns redu(;e 
the draft by an amount which can be roughly approximated as equal to 0.05 
inch for each turn. The turns which the gases make in leaving the damper 
box of a boiler, in entering a horizontal flue and in turning up into a stack 
should always be considered. The cross-sectional areas of the passages 
leading from the boilers to the stack should be of ample size to provide against 
undue frictional loss. It is poor economy to restrict the size of the flue and 
thus make additional stack height necessary to overcome the added friction. 
The general practice is to make flue areas the same or slightly larger than that 
of the stack; these should be, preferably, at least 20 per cent greater, and a 
safe rule to follow in figuring flue areas is to allow 35 square feet per 1000 
horse power. It is unnecessary to maintain the same size of flue the entire 
distance behind a row of boilers, and the areas at any point may be made 
proportional to the volume of gases that will pass that point. Tliat is, the 
areas may be reduced as connections to various boilers are passed. 

With circular steel flues of approximately the same size as the stacks, or 
reduced proportionally to the volume of gases they will handle, a convenient 
rule is to allow 0.1-inch draft loss per 100 feet of flue length and 0.05 inch 
for each right-angle turn. These figures are also good for square or rec- 
tangular steel flues with areas sufficient to provide against excessive frictional 
loss. For losses in brick or concrete flues, these figures should be doubled. 



Underground flues are less desirable than overhead or rear flues for the 
reason that in most instances the gases will have to make more turns where 
underground flues are used and because the cross-sectional area of such 
flues will oftentimes be decreased on account of an accumulation of dirt or 
water which it may be impossible to remove. 

In tall buildhigs, such as office buildings, it is frequently necessary in 
order to carry spent gases above the roofs to install a stack the height of 
wliich is out of all proportion to the requirements of the boilers. In such 
cases it is permissible to decrease the diameter of a stack, but care must be 
taken that this decrease is not sufficient to cause a frictional loss in the stack 
as great as the added draft intensity due to .the increase in height, which 
local conditions make necessary. 

In such cases also the fact that the stack diameter is permissibly 
decreased is no reason why flue sizes connecting to the stack should be 
decreased. These should still be figured in proportion to the area of the stack 
that would be furnished under ordinary conditions or with an allowance of 
35 square feet per 1000 horse power, even though the cross-sectional eirea 
appears out of proportion to the stack area. 

Loss IN Boilers — In calculating the available draft of a chimney 120 
pounds per hour has been used as the weight of the gases per boiler horse 
power. This covers an overload of the boiler to an extent of 50 per cent and 
provides for the use of poor coal. The loss in draft through a boiler proper 
will depend upon its type and baffling and will increase with the per cent 
of rating at which it is run. No figures can be given which will cover all 
conditions, but for approximate use in figuring the available draft necessary 
it may be assumed that the loss through a boiler will be 0.25 inch where the 
boiler is run at rating, 0,40 inch where it is run at 150 per cent of its rated 
capacity, and 0.70 inch where it is run at 200 per cent of its rated capacity. 

Loss IN Furnace — The draft loss in the furnace or through the fuel 
bed varies between wide limits. The air necessary for combustion must 
pass tlirough the interstices of the coal on the grate. Where these are 
large, as in the case with broken coal, but little pressure is required to force 
the air tlirough the bed; but if they are small, as with bituminous slack or 
small sizes of anthracite, a much greater pressure is needed. If the draft 
is insufficient the coal will accumulate on the grates and a dead, smoky fire 
will result with the accompanying poor combustion : if the draft is too great, 
the coal may be rapidly consumed on certain portions of the grate, leaving 
the fire thin in spots and a portion of the grates uncovered with the resulting 
losses due to an excessive amount of air. 

Draft Required for Different Fuels— For every kind of fuel and 
rate of combustion there is a certain draft with w hich the best general results 
are obtained. A comparatively light draft is best with the free-burning 
bituminous coals and the amount to use increases as the percentage of 
volatile matter diminishes and the fixed carbon increases, being higliest for 
the small sizes of anthracites. Numerous other factors, such as the thick- ' 
ness of fires, the percentage of ash and the air spaces in the grates bear directly 
on this question of the draft best suited to a given combustion rate. The 
effect of these factors can only be found by experiment. It is almost im- 

8—9 



1.3 

ii.i 

-i 1.0 

C 0.9 
S 0.8 
I 0.7 

Lf O.G 

(= 

I 0.5 
"g 0.4 

o 
"- 0.2 

0.1 

























































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1 






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15 



Fig. 8-5. 



15 20 25 30 35 

Pounds of Coal Burned per Sq. Ft, of Grate Surface per Hour 

Draft Required at Different Combustion Rates for Various Kinds of Coal 



possible to show by one set of curves the furnace draft required at various 
rates of combustion for all of the different conditions of fuel, etc., that amy 
be met. The curves in Figure 8-5, however, give the furnace draft necessary 
to burn various kinds of coal at the combustion rates indicated by the abcis- 
sae, for a general set of conditions. These curves have been plotted from 
the records of numerous tests and allow a safe margin for economically 
burning coals of the kinds noted. 

Rate of Combustion — The amount of coal which can be burned per 
hour per square foot of grate surface is governed by the character of the coal 
and the draft available. When the boiler and grate are properly propor- 
tioned, the efficiency will be practically the same, within reasonable limits, 
for different rates of combustion. The area of the grate, and the ratio of 
this area to the boiler heating surface will depend upon the nature of the fuel 
to be burned, and the stack should be so designed as to give a draft sufficient 
to burn the maximum amount of fuel per square foot of grate surface cor- 
responding to the maximum evaporative requirements of the boiler. 

Solution of a Problem — The stack diameter can be determined from 
the curve. Figure 8-4. The height can be determined by adding the draft 
losses in the furnace, through the boiler and flues, and computing from 
Formula 8-7 th? hsight necessary to give this draft. 

Example: Proportion a stack for boilers rated at 2000 horse power, 
equipped with stokers, and burning bituminous coal that wiU evaporate 

8-10 



8 pounds of water from and at 212 deg. fahr. per pound of fuel; the ratio 
of boiler heating surface to grate surface being 50: 1; the flues being 100 feet 
long and containing two right-angle turns; the stack to be able to handle 
overloads of 50 per cent; and the rated horse power of the boilers based on 
10 square feet of heating surface per horse power. 

The atmospheric temperature may be assumed as 60 deg. fahr. and the 
flue temperatures at the maximum overload as 550 deg. fahr. The grate 

surface equals 400 square feet. The total coal burned at rating = """" g ^"^-^ 
= 8624 pounds. The coal per square foot of grate surface per hour at rating 
= W = 22 pounds. 

For 50 per cent overload the combustion rate will be approximately 
60 per cent greater than this, or 1.60 x 22 = 35 pounds per square foot of 
grate surface per hour. The furnace draft required for the combustion 
rate, from the curve. Figure 8-5, is 0.6 inch. The loss in the boiler will be 
0.4 inch, in the flue 0.1 inch, and in the turns 2 x 0.05 = 0.1 inch. The 
available draft required at the base of the stack is, therefore, 

Inches 

Boiler 0.4 

Furnace 0.6 

Flues 0.1 

Turns 0.1 

Total T2 

Since the available draft is 80 per cent of the theoretical draft, this draft 
due to the height required is 1.2 -=- .8 = 1.5 inches. 

The chimney constant for temperatures of 60 deg. fahr. and 550 deg. 
fahr. is .0071 and from Formula 8-7, 

H - ill - "1 fe-^t- 

Its diameter from curve in Figure 8-4 is 96 inches if unKned, and 102 
inches inside if lined with masonry. The cross-sectional area of the flue 
should be approximately 70 square feet at the point where the total amount 
of gas is to be handled, tapering to the boiler farthest from the stack to a 
size which will depend upon the size of the boiler units used. 

Correction in Stack Sizes for Altitudes — It has ordinarfly been 
assumed that a stack height for altitude will be increased inversely as the 
ratio of the barometric pressure at the altitude to that at sea level, and that 
the stack diameter will increase inversely as the two-fifths power of this 
ratio. Such a relation has been based on the assumption of constant draft 
measured in inches of water at the base of the stack for a given rate of opera- 
tion of the boilers, regardless of altitude. 

If the assumption be made that boilers, flues and furnaces remain the 
same, and further that the increased velocity of a given weight of air passing 
through the furnace at a higher altitude would have no effect on the com- 
bustion, the theory has been advanced* that a different law applies. 

*See "Chimneys for Crude Oil," C. R. Weymouth, Trans. A. S. M. E., Dec, 1912. 
8—1 1 



Under the above assumptions, whenever a stack is working at its maxi- 
mum capacity at any altitude, the entire draft is utihzed in overcoming the 
various resistances, each of which is proportional to the square of the velocity 
of the gases. Since boiler areas are fixed, all velocities may be related to a 
common velocity, say that within the stack, and all resistances may, there- 
fore, be expressed as proportional to the square of the chimney velocity. 
The total resistance to flow, in terms of velocity head, may be expressed in 
terms of weight of a column of external air, the numerical value of such head 
being independent of the barometric pressure. Likewise the draft of a stack, 
expressed in height of column of external air, will be numerically independent 
of the barometric pressure. It is evident, therefore, that if a given boiler 
plant, with its stack operated with a fixed fuel, be transplanted from sea 
level to an altitude, assuming the temperatures remain constant, the total 
draft head measured in height of column of external air wiU be numerically 
constant. The velocity of chimney gases will, therefore, remain the same at 
altitude as at sea level and the weight of gases flowing per second with a 
fix^d velocity will be proportional to the atmospheric density or inversely 
proportional to the normal barometric pressure. 

To develop a given horse power requires a constant weight of chimney 
gas and air for combustion. Hence, as the altitude is increased, the density 
is decreased and, for the assumptions given above, the velocity through 
the furnace, the boiler passes, breeching and flues must be correspondingly 
greater at altitude than at sea level. The mean velocity, therefore, for a 
given boiler horse power and constant weight of gases will be inversely pro- 
portional to the barometric pressure and the velocity head measured in 
column of external eut wlU be inversely proportional to the squcU-e of the 
barometric pressiu"e. 

For stacks operating at altitude it is necessary not only to increase the 
height but also the diameter, as there is an added resistance within the stack 
due to the added friction from the additional height. This frictional loss 
can be compensated by a suitable increase in the diameter and when so com- 
pensated, it is evident that, on the assumptions as given, the chimney height 
would have to be increased at a ratio inversely proportional to the square 
of the normal barometric pressure. 

In designing a boiler for high altitudes, as aheady stated, the assumption 
is usually made that a given grade of fuel will require the same draft measured 
in inches of water at the boiler damper as at sea level, and this leads to mak- 
ing the stack height inversely as the barometric pressures, instead of inversely 
as the square of the barometric pressures. The correct height, no doubt, 
faUs somewhere between the two values as larger flues are usually used at 
the higher altitudes, whereas to obtain the ratio of the squares, the flues 
must be the same size in each case, and again the effect of an increased 
velocity of a given weight of air through the fire at a high altitude, on the 
combustion, must be neglected. In making capacity tests with coal fuel, 
no difference has been noted in the rates of combustion for a given draft 
suction measured by a water column at high and low altitudes, and this would 
make it appeeu* that the correct height to use is more nearly that obtained 
by the inverse ratio of the barometric readings than VvAr the inverse ratio 

8—12 • 



of the squares of the barometric readings. If the assumption is made that 
the vakie falls midway between the two formulae the error in using a stack 
figured in the ordinary way by making the height inversely proportional 
to the barometric readings would differ about 10 per cent in capacity at an 
altitude of 10,000 feet, which difference is well within the probable variation 
of the size determined by different methods. It would, therefore, appear 
that ample accuracy is obtained in all cases by simply making the height 
inversely proportional to the barometric readings and increasing the diameter 
so that the stacks used at high altitudes have the same frictional resistance 
as those used at low altitudes, although, if desired, the stack may be made 
somewhat higher at high altitudes than this rule calls for in order to be on 
the safe side. 

The increase of stack diameter necessary to maintain the same friction 
loss is inversely as the two-fifths power of the barometric pressure. 

Table 8-2. Stack Capacities, Correction Factors for Altitudes 

Altitude Height Normal ^ Ratio Barometer R ^ Ratio 

in Feet Above »„, .«.^to.- Reading Sea R- Increase in Stack 

Sea Level iJarometer j_g^g] ^^ Altitude Diameter 






. 30.00 


1.000 


1.000 


1.000 


1000 


28.88 


1.039 


1.079 


1.015 


2000 


27.80 


1.079 


1.064 


1.030 


3000 


26.76 


1.121 


1.257 


1.047 


4000 


25.76 


1.165 


1.356 


1.063 


5000 


24.79 


1.210 


1.464 


1.079 


6000 


23.87 


1.257 


1.580 


1.096 


7000 


22.97 


1.306 


1.706 


1.113 


8000 


22.11 


1.357 


1.841 


1.130 


9000 


21.28 


1.410 


1.988 


1.147 


10000 


20.49 


1.464 


2.144 


1.165 



Table 8-2 gives the ratio of barometric readings of various altitudes 
to sea level, values for the square of tliis ratio and values of the two-fifths 
power of this ratio. 

These figures show that the altitude affects the height to a much 
greater extent than the diameter, and that practicaUy no increase in diameter 
is necessary for altitudes up to 3000 feet. 

For high altitudes the increase in stack height necessary is, in some 
cases, such as to make the proportion of height to diameter impracticable. 
The method to be recommended in overcoming, at least partially, the great 
increase in height necessary at high altitudes is an increase in the grate sur- 
face of the boilers which the stack serves, in this way reducing the combus- 
tion rate necessary to develop a given power and hence the draft required 
for such combustion rate. 



8—13^^ 



CHAPTER IX 

Boilers 

The boiler equipment is the production center of the heating system 
and the point where the bulk of the operating expense is centered. For this 
reason, a heating plant can be successful and economical only if the boiler 
equipment is of correct type, good material and workmanship, well propor- 
tioned from the standpoint of its work and ample in capacity. 

Service from a heating system cannot properly be termed satisfactory 
unless the desired heating effect is secured without waste of fuel and without 
excess labor at the boilers, so it is the endeavor of this chapter to promote 
a better understanding of the boiler parts and what they should do. 

Due consideration should be given to the proper selection of a boiler, 
not only as to size and capacity, but also as to its adaptability to the existing 
local conditions which, if not properly considered, may affect the success of 
the entire plant. 

It is not intended in this discussion to cover any details of boiler con- 
struction, which properly come under the province of, and can best be solved 
by, the boiler makers themselves. 

Steam boilers have been built in one form or another for nearly two 
hundred years, yet today they are the least understood of all the important 
elements which make up a power or heating plant. 

Were no consideration to be given to the efficiency of the performance 
of a steeun boiler, such as the number of pounds of water evaporated by a 
pound of fuel, or the relation of grate surface to heating surface, etc.. the 
problem would be simple. 

Aff the years of experience and the thousands of evaporating tests 
made have not produced any definite and rehable rule or formula for cal- 
culating either the amount of steam that will be generated per hour with a 
given fuel or the quantity of steam in pounds produced per pound of fuel 
burned in the furnace. 

Lucke* says: "There is no absolute measure of boiler performance as 
to capacity or efficiency as a basis of comparison to measure the goodness 
of a bo'ler as a boiler; comparison must, therefore, be between one and 
another boiler, or one and another service condition ; one boiler may be said 
to be better than another, or one condition more favorable and another 
worse, for the result desired, but hardly more than this is possible." 

For commercial purposes, boiler capacities seem to be quite well stand- 
ardized, boilers used for heating work being rated in capacity of square 
feet of steam radiation, and boilers for power work in boiler horse-power. 

The boiler capacity rating in square feet is based on equivalent cast- 
iron direct radiation with a condensation rate of 34 lb. steam per sq. ft. per 
hr. 

The American Society of Mechanical Engineers in 1885 adopted a 
double definition of the "Boiler Horse-power" as follows: 

(a) The evaporation of 34.5 lb. of water per hour from and at 212 deg. 
falir. 

* Engineering Thermodynamics. 
9-1 



(b) The absorption by water, between fuel conditions and that of the 
steam leaving the boiler, of 33,305 B.t.u. per hr. 

A steam boiler consists of the following essential parts: A furnace in 
which the combustion of the fuel takes place; a vessel to contain water to 
be evaporated; a steam space where the steam is liberated and where the 
generated steam is contained ; a heating surface to transmit the heat of the 
furnace to the water; a smoke pipe to carry away the products of combustion, 
and various attachments or fittings, suph as gauges, damper regulators, safety 
valves, etc. 

A proper relation of the first four parts to each other constitutes a suc- 
cessful heating boiler. 

It is of prime importance that the furnace is of proper design as regards 
grate area, size of combustion chamber, ash pit, etc., to give most efficient 
operation, permitting the consumption of the maximum effective quantity 
of fuel per square foot of grate area. Further references will be made to 
importance of selecting the proper kind of grates for the various grades of 
fuel ava lable in Vcirious localities. 

The water space or the water-holding capacity of a boiler does not al- 
ways receive enough attention. It should be remembered that the boiler 
which- holds the greatest quantity of water at or near the normal water fine 
for given size or capacity is the safest one to use, because in such a boiler 
the water Lne is not so readily brought down to and below the danger point, 
as would be the case where there is only about half the water-holding ca- 
pacity. 

An investigation of the various cast-iron boilers to which our remarks 
regarding the water-holding capacity particularly refer, will show that there 
is an astonishing difference in this particular feature. Selecting two boilers 
of the same capacity but of different makes, it will be found that the water- 
holding capacity at or near normal water line varies as much as 1 to 4. 
It stands to reason that the boiler from which 4 gallons of water can be 
withdrawn by lowering the water fine Yl iiich will be safer than the boiler 
which shows a lowering of the water line by 3^ inch with loss of only one gal- 
lon. 

Boiler manufacturers recognize more and more that if a boiler is to be 
successful the steam space should be liberal. The velocity with which the 
steam bubbles are separated from the water in the liberating space is ex- 
tremely high. A boiler with limited steam-liberating surface will very 
Ukely lose its water under heavy load conditions because under the influence 
of this velocity particles are carried over with the steam into the piping system. 

Ihe heating surface of a boiler includes all parts of the boiler sheU, 
flues, tubes, etc., which are covered by water and exposed to the hot gases. 
Any surface having steam on one side and hot gases on the other is super- 
heating surface. 

The American Society of Mechanical Engineers recommends that in 
measuring heating surface, the side next to the gases be used. Thus when 
estimating the heating surface of water-tube boilers, the outside areas of the 
tubes are measured, and for return-tubular or fire-box boilers the inside 
areas eire measured. 

9—2 



The heat generated by the combustion of fuel permeates from the fur- 
nace through the heating surface to the water in the boiler. As the process 
of combustion proceeds, the heat liberated is immediately absorbed, partly 
by heat from the freshly added fuel, but mainly from the gaseous products of 
combustion. The absorption of heat by these substances causes a rise in 
their temperature and from these gases the heat is transmitted through the 
heating surfaces into the boiler water. This transmission of heat takes 
place in three distinct ways, each of which is governed by a definite law not 
applicable to the others. 

Before the heat reaches the body of the boiler water, it changes its mode 
of travel at least twice. It is first imparted to the heating surface : (a) by 
radiation from the hot fuel bed, the furnace walls and the luminous flames, 
and (b) by convection from the hot moving gaseous products of combustion. 
Upon reaching the heating surfaces the heat changes its mode of trans- 
mission and passes through the soot, metal and scale to the inner surface, 
which is in contact with the water,, purely by conduction. From the wet 
side of the heating surface the heat is carried into the boiler water mainly 
by convection.* 

The water in the boiler can absorb only that heat called the "heat 
available for the boiler," which is above its own temperature. Heat below 
this temperature will not flow into the boiler and is, therefore, not available 
for use. 

A commercial boiler absorbs only part of the available heat, which 
expressed as a percentage, is the true boiler effciency. This efficiency de- 
pends chiefly on the Eurangement of the heating surfaces. Therefore, from 
point of economy in operation, the heating surface available and its arrange- 
ment should be CEU-efuUy considered by the designer when selecting boiler 
equipment for a heating plant. 

The true boiler efficiency, which is the only true measure of the boiler's 
ability to gdDsorb heat, is expressed by the following equation: 

_, ... ^ , Heat absorbed by boiler 

1 rue. boiler emciency = — :rr-^ — ;; — ^ — ~ — 

Heat available tor boiler 

The efficiencies ordinarily used in commercial boiler tests do not rep- 
resent the true performance of the boiler under actual working conditions. 

Boiler capacities as given in catalogues of manufacturers of heating 
boilers are based on the efficiencies obtained in the testing laboratories, and 
as stated are not representative of true conditions. In selecting a boiler 
for a heating plant, due allowance should be made to take care of this dis- 
crepancy by adding a factor of safety to compensate for the difference in 
laboratory and actual working conditions. This allowance, which may 
be called the safety factor to be added to the theoretical capacity, varies 
widely for the various types of boilers. Before determining the safety factor 
to be added to the commerical rating, the designer should CEU-efuUy consider 
the type of boiler, the kind of fuel to be used, and the kind of attention the 
plant will receive, as all these bear on the performance and efficiency. 

The necessity of providing an extra safety factor is recognized also by 

* Bulletin 18, U. S. Bureau of Mines. 
9—3 



the heating trade and various trade associations that have established rules 
and regulations for the guidance of their members in determining boiler 
capacities. 

The difficulty in obtaining the more desirable grades of coal has re- 
sulted in an increasing tendency to use coals which are more readily obtain- 
able and lower in cost. The grates of the boilers should therefore be 
properly designed for the fuel which will most likely be used. Different 
authorities have a wide range of opinion as to the width of the air space 
that should be used between grate bar openings for a given grade of fuel. 

Professor Gebhardt recommends an air space of ^ inch between the 
grate bars and bars % inch wide for power boilers and for average bitu- 
minous coal. 

For No. 3 buckwheat coal an air space of 3/16 inch and for No. 1 buck- 
wheat 5/16 inch is recommended. 

Grate areas are usually determined in proportion to the heating surface 
of the boiler, that is, for a given fuel, the grate surface and heating surface 
have a fixed ratio. For normal operation, a ratio of grate surface to heat- 
ing surface of 1 to 35 to 45 develops the rated capacity of the boiler, while 
for fine coal or overload conditions, a ratio of 1 to 25 is desirable. 

For return-tubular boilers and water-tube boilers, the following table 
shows the usual ratios of grate surface to heating surface and also the grate 
bar openings applying with these ratios when using soft coal fuel. 

Table 9-1. Grate Surfaces for Soft Coah. 

^ , Grate Bar Openings Ratio grate surface to 

Coal heating surface. 

Mine Run Slack Mine Run Slack 

Va., W. Va., Md., Pa }^-in. Ys-in. 1:55 1:50 

Ohio, Ky.. Tenn., Ala ^-H H 1:50 1:45 

m., Ind., Kan., Okla Va - }4 M 1:45 1:40 

Col. andWy o Yi \^ 1:45 1:40 

Determination of the amount of grate surface to be used under given 
conditions involves the available draft as well as the fuel to be used. The 
curves given in Figure 8-0, page 00, show how much draft is necessary for 
burning different coals at various rates of combustion. 

The draft required to overcome resistances in the boiler is also given in 
Chapter 8, pages 00 and 00. These losses in the boiler and furnace must be 
deducted from the total available draft to determine the draft available for 
the fuel bed. 

The capacity of the boiler and the B.t.u. to be developed being known, 
the number of pounds of coal to be burned can be readily computed. The 
total grate area required is found by dividing the total number of pounds of 
coal to be burned by the rate of combustion taken from Figure 8-0, Page 00. 

Hand-fired, return tubular and water-tube boilers are readily operated 
at the rates of combustion in lb. of coal per sq. ft. of grate area given in 
Table 9-2. 

Small boilers of the residence-heating type usually burn coal at rates 
ranging from 1 to 5 lb. per sq. ft. of grate surface per hr. and in larger heating 

9-4 



Table 9-2. Ratios of CombiTstion for Various Coals. 



Anthracite 15 lb. per sq. ft. per hr. 

Semi-Anthracite ' 16 " " " " " " 

Semi-Bituminous 18 " " " " " " 

Eastern Bituminous 20 " " " " " " 

Western Bituminous 30 " " " " " " 



boilers the ratio ranges from 4 to 12 lb. per sq. ft. of grate surface per hr. 

These low rates of combustion are the result of demands for less fre- 
quent attention, in order that the man who fires the boiler may devote time 
to other work. In consequence, heating boilers are expected to do their 
work when fired once every hour or two or in residence heating, once in 6 
to 8 hours, whereas power boilers are fired at regular intervals of 5 to 10 
minutes.* 

Another reason why heating boilers require different firing methods 
to burn bituminous coals successfully is that the space in the fire-box above 
the fuel bed is usually very much smaller than is the corresponding space in 
power boilers.* This space, known as the combustion chamber, is where the 
smoky gases driven off from the coal must become mixed with air and burn. 
The more rapidly the combustible gases are driven off from the coal, the 
larger must be the space necessary for burning them completely. The 
relatively small combustion space in heating boilers makes it important 
that the firing be done in a way to prevent the gases from being driven off 
too rapidly.! 

The type of boiler to fit the given conditions most satisfactorily depends 
upon the physical conditions of the plant, as well as the type of heating 
system selected. The success of one depends upon the other. For this 
reason boiler selection is discussed also in Chapter 10, Selection of the 
Proper Type of Webster Heating System. 

On account of the great variation of governing conditions, no attempt 
will be made here to discuss in detail the method of installation of the boilers 
or their connections. 

Precautions should be taken in the design of the boiler plant to mini- 
mize bad effects from priming. 

Liberal bleeder or drip connections from the boiler header, connecting 
directly to the return header, eliminate a great percentage of this trouble. 

Priming in most cases is due to the presence of grease or oil in the boiler 
or to the presence in the water of certain alkalies which cause the water to 
foam or bubble, and be carried into the piping system by the steam. Before 
it can be expected to perform its functions uniformly, effectively and econom- 
ically, a boiler must be thoroughly cleansed of oil, scale, dirt and other im- 
purities. The priming of boilers is not confined to any particular type or 
make. The plant designer will safeguard the interest of the owner and him- 
self as well, if he makes sure that bleeder connections are made to protect 
the boiler in case of priming and that his instructions about proper cleaning 

* Technical Paper 180, U. S. Bureau of jMines. 

t For further reference to the importance and effect of combustion space see Technical Papers 63, 80, 
and 137 of the U. S. Bureau of Mines. 



^1 Rod threaded at Ends with 
yV'Pipe Sleeve over Rod must — ->! 
extend thru Bolt Holes in Diaphram 
Portion of Damper Regulator 



WEBSTER MODULATION VENT TRAP 
Vent Valve 

Overhead Return from 
Heating System 




Check Draft Door 



Fig. 9-1. Method of instaUing Webster Damper Regulator to a cast-iron sectional boiler. 

out the boiler and the entire heating system are carried out in full by the 
heating contractor. 

Damper control is an important feature of boiler operation. There are 
two classes of damper regulators, (1) those that move the damper for slight 
changes in the steam pressure, with a proportional movement due to the 
change in pressure and (2) those that operate the dampers between extreme 
positions when the steam pressure changes. The first is preferable from the 
standpoint of economical combustion. 

As mentioned in Chapter 8, the fuel in a steam-boiler furnace is made to 
burn by passing through it a ctirrent of eiir, which supplies the necessary 
oxygen and carries away the products of combustion. A liberal supply of 
available air is therefore very important. Yet in many cases the space 
Eillotted to the boiler room is inside, small and without adequate air supply 
for combustion. Boiler rooms should be of ample size and depth to ac- 
commodate the boilers without crowding, and should have an abundant 
supply of air for both combustion and ventilation. The space in front of 
the boilers should be ample for convenience and comfort. A cramped boiler 
room is not only unsightly, but it also adds to the difficulty of taking care of 
the plant efficiently. The attendant, when firing, has to stand about 43^2 or 
5 feet from the front of the furnace and usually about 12 to 18 inches to the 
left of a straight line running through the centre of the furnace door. He 
should have ample room to swing his scoop from the coal pile into any part 
of the furnace. 

Many a fireman is blamed for the poor economy shown by the plant he 
operates where the dissatisfaction should be at least partially charged to 

9—6 



WEBSTER 
MODULATION VENT TRAP 




Overhead Retun) 
from Heating System 



This Distance to „ 
be not less than 30 



Water Linej,ot Boiler. 



Drip from Bottom 

of Steam Header 

to connect to Return 

Header of Bovler 



With Thermostatic Control. 



^ Lock 



ViRod Threaded at ends with -5- 

3/4 Pipe Sleeve over Rod must 

extend through Bolt Holes in 

Diaphragm Portion of Dai 

Regulator. 

Remove Pin from Damper^ 

Regulator. '~ 




i 



^^team to. 
Healing 
System 



Vent Valve 

Overhead Return 
from Heating System 




Water Li ne of^ Boiler^ 



Drip from Bottom 

of Steam Header 

to Connect to Return 

Header of Boiler 



Note:- 

Damper Regulator Lever to Rest on 

Knife Edge in Slot of Damper Regulator 



With Time Clock Control. 

Fig. 9-2. Typical Applications of the Webster Damper Regulator to a Cast-iron Sectional Boiler in a 

Webster Modulation System. 

9—7 



the plant designer. It is difficult to keep skillful firemen in a small, poorly- 
kept bo.ler room. 

The size and type of boiler to be specified and the evaporation the boiler 
will give are problems a\ which the advice of the boiler maker may well be 
considered. The boiler maker is usually quite willing to co-operate if 
provided with such data as the total radiation in square feet and pounds of 
condensation, total condensation of the steam and return lines in equivalent 
square feet of radiation and pounds, the quality and size of fuel available, 
the size and height of chimmey and the firing period to be allowed. 



Steam Supply Main. 




Fig. 9-3. Method of making connections to boilers operating in parallel. Check valve on vent discharge 

trap only. 



9—8' 



CHAPTER X 
Selection of the Proper Type of Webster Heating System 

HAVING determined the heat requirements for a building or group of 
buildings, the decision as to the proper type of steam heating system 
involves selection from one of two main types: the Vacuum System 
and the Open-return or Modulation System. 

A Vacuum System, broadly speaking, is one in which the steam enters 
the piping at or slightly above atmospheric pressure, and in which the air 
and water are mechanically removed at the other end of the system, at a 
pressure less than that of the atmosphere. 

The Modulation System is one where the steam enters at a pressure 
slightly above atmosphere and the water and air of condensation flow by 
gravity to a point of disposal at which atmospheric or slightly lower pres- 
sure exists. 

Very often the decision rests upon the source from which steam may be 
obtained with greatest economy. If power is to be developed in the building 
or nearby, usually the exhaust steam from the engines or turbines can be 
utilized for heating, and a Vacuum System is selected because it provides 
the more economical means of steam circulation and of returning the water 
of condensation to the boilers. Where power is never available or desirable 
a"-, a means of circulation and where steam is generated at or obtained from 
a point of low pressure, a Modulation System is preferable. These two sets 
of conditions clearly indicate the proper selection of the type of heating 
system, but between them are many others where the desirability of either 
one or the other system is not so evident. Some conditions may even sug- 
gest a heating system which may be operated either on the vacuum or the 
modulation principle at will. 

The flexibility of Webster Systems of Steam Heating for adaptation to 
the widely different operating conditions makes possible a correct Webster 
System for every type of building. 

For instance, the Webster Vacumn System for a group of buildings 
spreading over considerable territory is quite different from that for a single 
compact structure, and a Webster Modulation System for a residence is 
often quite different from that for a hotel. 

The character of the building or the purpose for which it is to be used, 
therefore, often determines the particular type of Webster System for a 
maximum of comfort and operating economy. 

Grade may affect choice from among the various modifications of Web- 
ster Systems as the topography of the site may make the return of condensa- 
tion too difficult except by the use of a vacuum or even by direct pumping. 

The following pages describe the various types of Webster Heating 
Systems and the features which make each specially desirable for various 
classes of structures. 

10—1 



The Webster Modulation System of Steam Heating 

This is a highly efficient modern low-pressure system (see Figure 10-1) 
suitable for residences, store buildings, hotels and apartment houses, where 
live steam only is used for heating, either 
direct from heating boilers or from outside 
source. 

The initial steam pressure is closely 
controlled by means of an extremely sensi- 
tive Webster Damper Regulator. Con- 
densation is discharged automatically by 
gravity to the boilers or elsewhere through 
a Webster Modulation Vent Trap which 
operates without adjustment or attention 
even under fluctuating boiler pressures. 
The steam is admitted to each radiator 
throu2;h a Webster Modulation Valve which 
permits modulation of room temperature 
by simple hand manipulation. Condensa- 
tion is discharged and air vented from each 
radiator through a Wel)ster Return Trap, 
whichmaintaiu'^full heating efficiency of the 
radiation and eliminates the annoyances, 
dilficulties and noises common to ordinary 
gravity steam heating systems. 

Condensation and air from each radi- 
ator flow by gravity through a system of 
return risers and mains into the Webster 
Modulation Vent Trap, where the air is 
automatically vented, permitting the sys- 
tem under favorable boiler conditions to op- 
erate for long periods under partial vacuum, 
or "vapor," but also due to flexibility of 



A'£BSTEft DAMPER fl£GL 



k^==m- 




333; 




Fif?. 10-1. Typical Arrangement of the Webster Modulation System of Steam Heating 



10^2 



the system permitting higher pressm-es to be carried in severe weather when 
a maximum amount of lieat-is required. 

In addition to its saving of fuel and the feature of convenient inde- 
pendent temperature control for each room at the will of the occupant, the 
Webster Modulation System has a special advantage in its simplicity of 
operation. No expert attendance is required at any time and in most 
cases the attention which must be given to the operation of the system is 
merely the firing of the boiler at long and infrequent intervals. 

The response of the Webster Modulation System to demands for changes 
in the rate of heating is almost immediate. A cool room or building can be 
heated quickly upon demand or if too hot, the temperature can be as easily 
and as quickly reduced. 

In its simplest form, the Webster Modulation System consists of a cast- 
iron boiler, with its appurtenances, a system of supply piping, radiating 
surfaces with a Webster Modulation Valve at the inlet and a Webster Re- 
turn Valve at the outlet of each, a system of return piping and a Modulation 
Vent Trap for removing air and for returning water to the boiler, all as 
previously described. 

This is the Modulation System which would ordinarily be selected for a 
residence and usually for the smaller apartment, store, office and public 
building and for hotels and churches of moderate size. 

Residences: The Modulation System with cast-iron boilers is most 
suitable from every standpoint for a residence, whether a thirty-room 
house or a five-room bungalow. 

The designer of heating plants for residences, is in most cases confronted 
by two conditions which decide the type of boiler he shall use, first, smallness 
of the boiler room and, second, the low head-room in the basement. Both 
suggest the use of the cast-iron type boiler because of its compactness and 
low water line. 

The prospective owner is particularly interested in the attention neces- 
sary for operation. Whether he attends to the heating system himself or 
employs someone else, he desires a plant requiring minimum attendance. 

Except for the periodical feeding of coal and removal of ashes, the at- 
tention required by a Modulation System is neghgible. 

Apartment Buildings: The Modulation System is particularly adaptable 
here unless the building spreads over too much ground or the open-return- 
line system could not be properly graded without too much complication. 

Apartment buildings are erected for the revenue which they will bring 
to their owners, and a heating plant which can be operated with greatest 
fuel saving and least janitor service is the best-paying proposition. 

Control of the amount of steam admitted into each radiator independ- 
ently gives the occupant of each room or apartment a convenient means 
of temperature regulation. 

The small amount of attention required by a Modulation System gives 
the janitor of the building more time for his other duties. 

Store Buildings: Store buildings of the smaller size, where no mechan- 
ical system of heating and ventilation need be provided, and where an open- 

10—3 



return-line system can be applied, take the same type of heating system as 
described for residences and apartments. 

Office Buildings: Smaller and medium-sized buildings for office and other 
commercial purposes, telephone exchange buildings, etc., where the steam 
requirement is for heating purposes only and where the architectural features 
permit an open-return-line gravity heating system, can also utilize the Web- 
ster Modulation System to advantage. 

The basement rooms as a rule are heated by radiating surfaces placed 
overhead, so that the return lines can be arranged for a gravity return to the 
Modulation Vent Trap and then to the boiler, eliminating all mechanical 
return-handling devices and their complications. 

Inasmuch as any one who is able to handle a shovel can fire and operate 
the Webster Modulation System, after being given one lesson in its care and 
maintenance, this system will materially aid the owner in keeping his labor 
costs low. 

Hotels: Big city hotels, being usually equipped with modern and com- 
plete mechanical equipment from which exhaust steam is available, can 
more profitably use the Vacuum System. However, great strides have been 
made in recent years by the country towns to provide more convenient 
hotel accommodations for the traveling public, and a great number of high- 
class hotel buildings which have proved excellent advertisements for their 
towns have come into existence. 

The owner of such a hotel, while not in a position to equip with the 
many refinements of big metropolitan hotels, is anxious to have his guests 
provided with clean, comfortable and properly heated rooms, and is willing 
to pay the price for an efficient and economical heating plant. 

The Webster Modulation System of Heating is particularly advantage- 
ous in this type of building, giving all that can be asked in heating effect, 
and enabling the janitor or so-called engineer, who is in many cases also the 
porter, bell boy and general utility man, to take care of his many other 
duties. 

Churches: Churches where no mechanical ventilation is to be provided, 
and where all rad'ation can be placed high enough above the water line for 
gravity return of the water of condensation to the boiler, are properly 
equipped with the Modulation System. 

fieating plants in churches as a rule do not receive the best of attention, 
and therefore the simpler the installation, the more satisfactory the service. 
The operation of the Modulation System in draining the condensation back 
to the boiler entirely by gravity also avoids the noise that usually accom- 
panies the action of mechanical devices where the latter are employed for 
handling condensation. 

Heating systems in churches are usually operated intermittently, and 
for this reason must be laid out with due precaution to avoid freezing — 
a condition which is met in the Modulation System by eliminating the use 
of wet returns. 

Public Buildings: In this classification may be included schools, court 
houses, post-offices, libraries, etc., which are not to be provided with mechan- 
ical systems of ventilation, but where the ventilating systems are to be of 

10—4 




Fig. 10-2. The entrj of a modern apartment building showing heat outlets in the side walls. 



10— 4a 



the indirect or direct-indirect gravity ventilation type. Such buildings 
have, as a rule, no other mechanical equipment besides the heating and ven- 
tilating plant. The Webster Modulation System with an open return line 
is recommended for these structures. 

This class of buildings usually has intelligent men in charge of the opera- 
tion and maintenance of the heating plant, so that the application of mechan- 
ical devices for handling the water of condensation would not be as objec- 
tionable as would be the case with the other types of buildings. 

There is no advantage, however, in providing these mechanical devices. 
Their use should therefore be hmited to cases where an open-line gravity 
return to the boiler does not work out satisfactorily. 

Where public buildings, such as schools, are heated intermittently, 
proper provisions should be made to guard aeainst freezing. Bottom supply 
connections should be used for all direct-indirect radiation. 

Wet returns should also be eliminated as much as possible in such 
buildings, and where their ehmination is not possible they should be properly 
protected a^;ainst freezing. 

With Fire Box Boilers: The foregoing discussion of iJie Webster Modu- 
lation System has favored cast-iron type boilers for buildings of moderate 
size. 

Fire-box boilers can be used to advantage in buildings of somewhat 
larger proportions. 

Rules and regulations in force in some communities specify maximum 
permissible size limits for cast-iron boilers and require that steel boilers of 
the fire-box type shall be used where the load requirements exceed the 
specified limit. 

From a strictly engineering standpoint, good practice bases the limit 
of size of the cast-iron boiler upon the grate surface. The installation of 
cast-iron boilers which have a grate over 72 inches in length should not be 
permitted, as a grate over 6 feet in length makes difficulties in firing. 

Street Steam: In localities where street steam is available with unin- 
terrupted service guaranteed for the entire heating system, and where the 
rate does not exceed that at which steam can be generated in an individual 
plant, the installation of the Modulation System with street steam supply 
provides ideal heating for almost any type of building. 

The reduced first cost of the heating plant and its installation and the 
fact that such a plant requires almost no operating attention, make this 
arrangement very attractive from the owner's standpoint. 

The Service Company supplying the building provides the service steam 
line to which the heating contractor can make his connection. The water 
of condensation is discharged to the sewer through a^pieter in the return line, 
except where a flat rate per square foot of radiatioirts charged, in which case 
no meters are used. 

This type of heating system can be installed in almost any type or size 
of building, except where too extensive area prevents satisfactory arrange- 
ment of the return line for gravity open-return circulation. 

10—5 



Systems with Open Return to Pump and Receiver 

The buildings for which this type of heating plant is recommended 
require high-pressure steam for various purposes. Among these buildings 
are hospitals, Y. M. C. A. buildings, restuarants, etc. The steam supply 
cjmes from one or more high-pressure boilers. That for heating is reduced 
to suitable pressure by means of a pressure-reducing valve and is cir- 
culated through the boating system by gravity — that is, the water of con- 
den ration is returned to the vented receiver of an automatic steam-operated 
pump and receiver. The receiver has a float at its water level, the rise and 
fall of which controls the steam through an automatic valve to the pump. 

The pump is operated by high-pressure steam, and its exhaust, after 
extraction of the oil by an oil separator, is utilized in the heating system. 

Hospitals: The modern hospital has considerable steam-using equip- 
ment, such a3 sterilizers, blanket warmers, steam cookers, dish-washing 
machines, laundry ma 'hinery, etc., which requires steam at pressures rang- 
ing from 30 to 90 lb. 

Reduction to the intermediate pressures and to the low pressure for 
heat ng purposes is effected by means of pressure-reducing valves. 

The operat'ng man in a hospital plant is in most cases a capable licensed 
engineer, but his duties are many and this fact should not be overlooked 
in the design of the plant. The heating system should combine simplicity 
in de ;ign. fuel efficiency, noiseless operation and flexibility of heating — all 
of which requirements are fully met by the Webster Modulation System. 

Y. M. C. 4. Buildings: These buildings resemble hotels in many 
respects, as, in addition to the recreational features, hotel accommodations 
are provided for members. Restaurant and cafeteria service are maintained, 
as well as swimming pools, Turkish baths, etc. in connection with which 
there is a demand for high-pressure steam in addition to the low-pressure 
steam needed for heating. For this reason all of the condensation cannot 
be returned directly to the boilers. 

The heating system should be of a type which permits regulation of the 
supply of steam to the bedrooms, according to whether they are occupied 
or empty. The graduated control system of steam supply to the radiators 
by means of Webster Modulation Valve is therefore the most logical system 
to adopt. A steam-operated pump and receiver takes care of the returns 
from all the steam-using equipment and also from the Webster Modulation 
System. 

Hotels and Restaurants: Assuming that the kitchen equipment is to 
be supplied with steam and that the mechanical equipment of the heating 
plant must be simple, a consideration of the various types of heating systems 
wiU readily suggest the Webster Modulation .System with an open-return 
line to a pump and receiver, using reduced-pressure steam for heating and 
taking steam directly from the boiler at the pressure required for the other 
equipment. 

This type of heating system in buildings of this class is limited only 
by the area covered by the structure. Ruildings extending over considerable 
ground may require special provision for handhng the return. 

10—6 




Fig. 10-3. Arrangement of cast-iron wall radiation in cove of ceiling in a griU room. 




Fig. 10-4. Cast-iron wall radiation in garage. The radiation is placed to avoid being damaged 
by cars and to prevent injury to tires from heat. 



10— 6a 



Schools in Rural Districts: Rural school buildings seldom have elec- 
tricity available for operating the fans of mechanical systems of ventila- 
tion, or for operating pumps supplying water from artesian wells. 

A steam engine is necessary to operate the ventilating fan and a steam- 
operated pump is required for the water supply system. 

The boilers in such cases are usually operated at about 30 lb. and the 
steam for heating purposes is reduced to about 1 lb. pressure. The exhaust 
steam from the engine and pump is utilized in the heating system, after ex- 
traction of the oil by passing the steam through an oil separator. A by- 
pass connection is provided in the exhaust pipe, which extends into the at- 
mosphere, so that at such times as the heating system is not in operation 
the exliaust steam may be discharged into the air. 

The Webster Modulation System for use under these conditions is de- 
signed with an open-return line and with a steam-operated pump and re- 
ceiver which discharges the water of condensation back into the boiler. 

The Webster Open Return Line System (without Modulation 
Valves) : This type of heating system is identical in principle and method 
of operation with the Webster Modulation System previously described, 
except that standard type radiator valves are used in the supply connections 
to the radiators in place of Webster Modulation Valves. This system is 
recommended where an open-retin-n-line system, either returning directly 
to the boilers or to a pump and receiver, can be used and where only large, 
open rooms are to be heated, as in department stores, loft buildings, ware- 
houses, etc. Buildings of this type, with heated spaces usually containing 
a number of radiators, do not require Webster Modulation Valves in the 
supply connections to the radiators, inasmuch as a fair degree of temperature 
regulation may be obtained by shutting off one or more radiator units. A 
heating plant of this type costs less than a complete Webster Modulation 
System, and may be selected where a reduced first cost of installation is 
necessary. 

If the building conditions permit the water of condensation to be re- 
turned to the boiler by gravity, the heating plant is very simple and requires 
little attention outside of boiler firing. 

Conditions are sometimes met, especially in department stores, where 
the condensation cannot be returned to the boiler by gravity, in which case 
the installation of an automatic condensation pump becomes necessary. 

Loft buildings used for light manufacturing purposes, requiring live 
steam for various uses, such, for instance, as in tailoring establishments and 
plating works, demand either a separate high-pressure boiler to supply steam 
for the process work, or an entire boiler plant operated at high pressure, 
with reduced pressure for the heating system supply. 

The Webster Modulation System with Vacuum Pump Relay: 
This is a combination of the Webster Modulation and Vacuum Systems 
which may be operated as an open-return-line system, returning the 
water of condensation to the boiler by gravity, or as a Vacuum System, 
with electrically operated vacuum pump to remove the water of condensa- 
tion and air from the heating system and to discharge the water into the 

10—7 



boiler. It is particularly advantageous in schools and theatres having 
mechanical systems of ventilation which are in operation only part of the 
time. 

In a school building, for instance, the ventilating system is usually put 
into operation at about 8 o'clock in the morning and is shut down at 4 o'clock 
in the afternoon. While the ventilating system is in use, the plant operates 
as a Vacuum System. As soon as the ventilating system is shut down the 
vacuum pump may be stopped and the direct heating system is then operated 
as an open-return-line system discharging the retm-ns through a modulation 
vent trap to the boiler by gravity. During the night the heating plant re- 
quires almost uKj cittenti'u. 

As the vacuum pump is not operated 24 hours per day, the heating of a 
theatre may be accomplished in very much the same manner. In this 
instance, however, the ventilating system is in use in the afternoons and 
evenings, during which the plant is operated as a Vacuum System. After 
the close of the night performance, the change is made to operation as a 
Modulation System. 

This type of system must always be so designed that the pressure drop 
through the entire system will not be less than the net static head between 
the modulation vent trap and the water line of the boilers. 

The Webster Vacuum System of Steam Heateng 

Briefly, the Webster Vacuum System is a method of circulating exhaust 
or low-pressure live steam, or a cambination of the two, with minimum 
initial or back pressure, and with entire freedom from water-hammer, air 
pockets, leaky air valves, and all of the other annoyances which are common 
with ordinary steam heating systems. 

A partial vacuum is mechanically created and maintained by means of 
exhausting apparatus, which consists of steam-driven or power-driven vac- 
uum pumps of suitable design and capacity. 

A typical arrangement of the Webster Vacuum System is iUustrated 
in Figure 10-3. 

The exhaust steam from the engine passes through a Webster Oil 
Separator, dripped through Webster Grease Trap, thence to the heating 
system. A pressin-e-reducing valve with by-pass is provided to make up 
any deficiency in the volume of exhaust steam or to provide live steam for 
heat'ng when the main engine is shut down. 

The supply main is dripped as it enters the building, through a Webster 
Heavy-duty Trap, protected by a Webster Dirt Strainer. The steam supply 
risers in larger buildings may have to be dripped through additional Webster 
Traps of the proper size and type. 

Steam is supplied to the various types of heating units through Webster 
Modulation Valves, although the system will work smoothly with auto- 
matic temperatiu-e control. Some of the radiator units are shown with 
ordinary supply valves. Each heating unit is drained through a Webster 
Return Trap into the return risers ; and the larger heating coils are protected 
by Webster Dirt Strainers, 

10—8 



Steam is also supplied to temperiBg and reheating coils which are also 
drained at the return ends of each group through Webster Traps protected 
by Webster Dirt Strainers. 

The returns all join and lead to a vacuum pump, protected by a Web- 
ster Suction Strainer. The steam supply to 
the pump is automatically controlled by a 
Webster Vacuum-pump Governor. Com- 
pound gauges mounted on a slate board 
and having connections to the heating main 
and the vacuum return line give an indica- 
tion as to the internal steam conditions. 

The vacuum pump discharges through 
a Webster Air-separating Tank to a Webster 
Feed-water Heater, usually of the Webster 
Preference Cut-out Type, with oil separator 
constructed to direct a sufQcient quantity 
of exhaust steam toward the heater. The 
balance of the exhaust steam is available 
for the heating system. Any excess of 
exhaust steam over feed-water and heating 
needs escapes through 
valve. The heater may thus be cut out of 
service while the oil separator remains in 
use. 

The ventilation scheme provides a 
supply of purified, humidified and heated 
fresh air for those rooms which it serves. 
The air is partially heated in passing over 
the tempering heater, and is drawn by the 
fan through the reheater into the main air 
supply duct. The supply of steam to the 




10-2. 



Typical Webster Vacuum System of Steam Heatin;», showing arranKenienI of the power plant 
apparatus, mains, radiation surface anri various accessories. 



] 0—9 



tempering heater and reheater coils is automatically governed by the tem- 
perature control valves. 

The typical illustration, Figure 10-2, represents a Webster Vacuum 
System in a plant where steam is generated in high-pressure boilers for power 
purposes and where the exhaust steam is used for heating. It is not intended 
to portray a standard arrangement for all conditions. 

A Vacuum System with low-pressure boilers requires an electrically 
operated vacuum pump for returning the water of condensation from the 
heating system to the boilers. This arrangement should be selected where a 
gravity return to the boiler cannot be arranged, and where the plant is of 
such a nature that an open-return-line system with an electrically operated 
condensation pump is not practical. It is also assumed that mechanical 
equipment, aside from that of the heating system, does not require high- 
pressure steam, so that the installation of low-pressure boilers is logical. 

Electrically operated vacuum pumps, especially of the rotary type, 
have reached a high state of perfection, so that the attention required by the 
pump is reduced to a minimum. 

The principal advantages from a properly installed and operated Web- 
ster Vacuum System are as follows : 

1. The circulation of steam is quick, positive and uniform. All sur- 
faces are heated in a relatively short space of time after steam is turned into 
the system. 

2. Water-hammer in the piping is unheard of, due to the continuous 
rehef of air and the positive removal of the products of condensation. 

3. The radiators are maintained at 100 per cent heating efficiency 
due to the complete removal of air and water. The absence of air-valves 
on the radiator eliminates one of the most annoying features of many 
steam-heating systems. 

4. Saving in operating cost is accomplished practically by eliminating 
back pressure upon steam engines. This either saves directly in fuel cost 
or pennits the engine to do more work at the same expenditure of fuel. 

5. Saving is effected through the ability, during mild weather, when 
the demands for heating are shght, to distribute a relatively small volume of 
steam throughout the system as needed, with a pressure at, or even slightly 
below, that of the atmosphere. This small volume of steam can be thor- 
oughly distributed only where the Vacuum System principle is employed. 
In tliis country mild weather constitutes about 75 per cent of each heating 
season, '"moderately" cold weather about 20 per cent and only 5 per cent 
can be classified as "severely" cold. 

6. Saving of fuel results from utilizing the condensation and its con- 
tained heat as part of the boiler feed. The returns, being practically dis- 
tilled water, are excellent for the boilers, as Webster Oil Separators remove 
the cylinder lubricant before the exhaust steam goes into the heating system. 
In some cases little new or make-up boiler water is needed. 

To these advantages should be added comfort and convenience. More 
and better work is obtained from the occupants of properly heated build- 

itv— 10 



ings, and this too adds to the general feeling of satisfaction from the Webster 
System. Some of the savings are difficult to measure in actual doUeu-s and 
cents, but they are nevertheless substantial. 

Buildings for which the Webster Vacuum System is selected are usually 
of large proportions. Consequently the first and installation costs are less 
than for an open-return-line system on account of using smaller pipe sizes 
for both the supply and return lines. 

Where hfts are necessary in the returns the Vacuum System is the only 
solution. 

From the operating standpoint, the Vacuum System with an electrically 
operated vacuum pump of the rotary type is as simple as the open-return- 
line system with a condensation pump. 

For a large building or a group of buildings the Vacuum System with 
low-pressure boUers is the logical choice, and it is particularly recommended 
for high buildings of any description, buildings occupying considerable 
area, buildings of any description in which lifts in the returns are necessary, 
and groups of buildings to be heated from a common boiler plant. 

High Office Buildings: The pumps required for elevators and for water 
supply are usually steam-driven, even if the building does not have its own 
power plant. The exhaust steam from these pumps can and should be 
utilized in the Webster Vacuum System. 

The Modern First Class Hotel: Most buildings in this class are provided 
with high-pressure steam boiler plants, either for generating their own 
electric power, or in case the electric current is purchased, for operating the 
pumping equipment, and furnishing the steam for kitchen and laundry 
purposes. The Vacuum System with steam-operated vacuum pumps is the 
proper type for heating such buildings. 

Hospitals: As already mentioned in connection with the Modulation 
System (See page ), these institutions require high-pressure steam for 
kitchen, laundry and steriUzing purposes, making it necessary to have a 
high-pressure boiler plant. Many of the larger hospitals have their own 
electric power plants, and use steam for operating the refrigerating machin- 
ery and pumping equipment. The heating system in such institutions 
should utihze the available exhaust steam, as is best accompUshed in a 
Webster Vacuum System. 

Manufacturing Plants: The selection of a vacuum system for a manu- 
facturing plant is usually justified where high-pressure steam is needed for 
process work, and the conditions are such that cheap electric power is not 
ava'lable. In such cases high-pressure boilers, and the necessary electrical 
machinery for generating cm-rent are installed and exhaust steam is utilized 
for heating. 

The Webster Conserving System : The Webster Conserving System 
(Figure 10-3) is specially designed for heating where the boilers are to be 
operated by unlicensed engineers, and where there are steam requirements 
for other than warming purposes. 

Laws of various states prohibit steam pressures greater than 10 lb. per 
sq. in. in boiler plants which are in charge of unlicensed engineers. These 
laws have led to attempts, in plants where steam at from 5 to 10 lb. was 

10—11 



wresTER 

CONSERVING VALVE 



Tills CmnieclTim to be itredo 1 S*- O" 
from Pressure Reducing Valve 




^WEBSTER HORIZONTAL 
OIL SEPAHATOn 



/This Valve to be open when 
Pump is started and closed 
when Pump is in operation 



^Globe Valve 
-Check Valve 



By-pass to Sewer^ 



WEBSTER SUCTION STRAINER 



\WEBSTER GREASE 
AND OIL TRAP 



Fig. 10-3. Typical layout of a Webster Conserving System. 

necessary for process work, to operate vacuum pumps by low-pressure steam, 
the pumps discharging the condensation through a receiver into the boilers. 

Unfortunately it has proven almost impossible to control these low boiler 
pressmes and tuc pmnp upeiation has been erratic. When the boiler pres- 
sure dropped and the pump stopped or failed to work properly, the condensa- 
tion was not returned to the boilers. The water level was often lowered to 
a dangerous point and in many instances serious damage resulted to the 
boilers. 

These diificulties are entirely overcome in the Webster Conserving 
System, the main feature of which is the Webster Conserving Valve, de- 
signed to prevent the admission of steam into the heating system until a 
certain predetermined steam pressure is reached. The pressure at which 
the valve will open is slightly above that required to operate the vacuum 
pump, so that the pump starts to operate before any steam is admitted 
into the heating system. If the boiler pressure drops, due to irregular firing 
or to other causes, so that the heating system receives no steam, or if the 
steam is purposely cut off from the heating system, the pump, taking its 
steam from the boiler header directly, continues to operate and thus insures 
the return of all condensation and the avoidance of damage to the boiler 
which might otherwise occur. 

A pressure-reducing valve is installed on the low-pressure side of the 
conserving valve to prevent pressure from building up on the heating main 
beyond any desired point. 

The exhaust steam from the vacuum pump is utilized in the heating 
system after the oil is extracted by means of a Webster Oil Sepeirator. There 
is, therefore, practically no cost for power for steam circulation. 

10—12 



An additional feature of economy lies in the fact that the use of only 
one pump, acting as both vacuum pump and boiler-feed pump, minimizes 
the attention required for operating the system. The use of a single pump, 




Fig. 10-4. Typical installation and close-up of the Webster Conserving Valve 



10-1.3 




Fig. 10-6, Cast-iron wall radiation arranged under the saw tooth of a factory. 




Fig. 10-7. Arrangement of cast-iron wall radiation on side walls of a factory building. 



10— 13a 



however, is recommended only where steam pressure maintained on the 
boilers is within 15 lb. per sq. in. For higher boiler pressures, the excessive 
pump capacity necessary to compensate for the high back pressure on the 
pump discharge makes a separate boiler-feed pump desirable. 

The application of the Conserving System should be limited to plants 
where the steam pressure on the boiler ranges from 5 to 15 lb. 

Application of the Conserving System to Large Industrial 
Plants: A study of steam engine performance, where the engine exhausts 
into the atmosphere or into the heating system against a back pressure 
slightly above that of the atmosphere, shows that engines working under 
such conditions actually convert only 5 to 10 per cent of the heat supplied 
to them into mechanical energy. The remaining 90 per cent of the heat 
originally supphed to the steam entering the engine is retained in the ex- 
haust steam. 

In some plants, power and heating loads are nicely balanced so that all 
the exhaust steam available from power units can be utilized for process 
work or heating purposes, in which event the 90 per cent of heat energy re- 
maining in the exhaust steam is put to useful work. In such cases the engine 
may be considered as a pressure-reducing valve which reduces the pressure 
from that carried on the boilers to that required for heating and process pur- 
poses. 

There are numerous industrial plants where the power load is greatly 
in excess of the heating load, so that the quantity of exhaust steam ava'lable 
is greatly in excess of that actually required. The surplus exhaust steam 
with its heat units must then be wasted. 

Where these conditions exist the engines are often operated condens'ng 
instead of ncn-condensing, so that exhaust steam from the auxiliary machin- 
ery only is available. In most instances the quantity is not sufficient to 
supply the heating load, and the deficiency is made up by live steam supplied 
from the boiler through a pressure-reducing valve. 

The work done by the pressure-reducing valve in reducing the steam 
from boiler pressure to that required in the heat.ng system is converted into 
superheat on the low-pressure side of the valve. This work represents 
about 10 per cent of the total heat energy supplied to the steam. If this 10 
per cent of heat energy can be utilized by conversion into mechanical energy, 
nearly ideal conditions will be approached. 

Various attempts have been made in the past to improve the economy 
of power and heating plants by endeavoring to utilize the exhaust steam from 
the receivers of compound engines. This exhaust is bled into the heating 
system and the deficiency made up by admitting live steam into the receiver 
through a pressure-reducing valve. In determining the advisabihty of this 
form of application, the effect of the relations between heating and power 
load and the relative proportion of the cylinders so vitally affects the economy 
that in each instance special consideration has to be given to all elements 
entering. 

The Webster Conserving System can be applied to this problem. In 
the same manner that the conserving valve is applied to conserv^e the pres- 
sure on the boiler by preventing the escape of its steam until a certain pre- 

10—14 



determined pressure is obtained, it can be applied to the receiver of a com- 
pound engine, opening and admitting steam at receiver pressure into the 
heating system, when the pressure on the receiver exceeds that which is 
necessary for the proper operation of the low-pressure cylinder, and closing 
when the receiver pressure drops below the point for which the conserving 
valve is set. 

The quantity of steam taken from the receiver is made up by changing 
the cut-off on the high-pressure cylinder so that the high-pressure side acts 
as a pressure-reducing valve for the steam required for heating purposes. 
In expanding from boiler pressure to the receiver pressure, the heat energy 
given up in the expansion is converted into useful mechanical energy. 

By means of the Webster Conserving System many existing power and 
heating plants may be brought to efficiency where they are otherwise 
wasteful of st am. 

The Webster Hylo System: Where a number of buildings must be 
heated from a detached central plant, or where a building covers con- 
siderable ground, the soiu"ce of steam supply and of vacuum cannot always 
be located to make a well-balanced system. 

The largest building in the group may, for various reasons, be farthest 
from the source of supply, and may also be the lowest point in the system of 
retm"n piping, thus making it doubly difficult to secure perfect heating and 
easy return of condensation. Nearby points may be favored with unnec- 
essary "pressure d.fference." 

Attempts have been made to solve this problem by running the supply 
and return mams in reverse direction, so that the point of highest pressure 
is the point of lowest vacuum and inversely, thus maintaining, in some degree, 
the same differential between supply and return pressures. 

Where the largest building is at a low point away from the source of 
supply, it is obviously impracticable to solve the problem in this way. 
Furthermore, such a plan does not allow for extensions to or expansion of 
the plant, uiiless the new buildings can be located to suit the piping scheme 
irrespective of the manufacturing need. 

This problem has been solved with unqualified success by Webster 
Hylo Vacuum Controlling Sets, which are installed at certain points in the 
return line to restrict the vacuum to just the amount necessary for proper 
circulation and drainage at nearby points where high vacuum is not needed. 
The high vacuum is carried to extreme or low points where high vacuum is 
required. The result is a well-balanced system with perfect circulation in 
all parts. 

The operation of the vacuum pump is also improved to a marked degree 
as the degree of initial vacuum is reduced, making it unnecessary to use or 
waste cold water to condense the vapors arising from the hot water returned 
under high vacuum. Sometimes smaller pumps may be used, or the pumps 
may be operated at slower speed, with less wear and tear. 

The Webster Hylo Sets consist of a Webster Hylo Trap, a Webster 
Hylo Vacuum Controller, Webster Hylo Vacuum Gauges, and when needed, 
a Webster Lift Fitting. 

10—15 




Fig. 10-5. Connections around 
Webster Hylo System equip- 
ment where the low-vacuum 
return main drops from over- 
head and discharges through 
a Webster Hylo Trap to the 
high vacuum return main. 



Floor Line^ 



lauge Cock 



Fig. 10-6. Typical installation 
of Webster Hylo Trap, Con- 
troller and Gauges where high 
and low-vacuum returns are 
on the same level. 




-Gate Valve 



Connect to High 
Vacuum Returns 

/ /^ WEBSTER 
.IFT 
FITTING 




By- Pass on Side 



Fig. 10-7. Arrangement 
of the Webster Hylo 
Controller, Trap and 
Gauges where the low- 
vacuum return is lifted 
to the high-vacuum 
return. 



10—16* 



CHAPTER XI 
Pipe Sizes for Webster Systems 

A. Flow of Steam Through Pipes : Flow of steam through piping is 
caused by difference in pressure, which diminishes continually from the 
source to the outlet, due to frictional resistance, deflection, contraction and 
expansion. Likewise there is a continual drop in temperature due to the 
transmission of heat through the walls of the piping. 

Steam at initial pressure and density, but without material velocity, as 
in a boiler, requires a certain pressure drop, to impart initial velocity in the 
main. This drop varies with the velocity required, density of steam and 
shape of the orifice at entrance of the main. The pressure drop or head 
required for a given velocity, as of initial density at a point about three 
diameters beyond the entrance of a steam main, with sharp entrance edge, 
has been found from tests of the weight of low-pressure steam passing 
through a cyUndrical sharp-edged orifice of length equal to three diameters. 
The pressure difference or head (hi) necessary to produce such velocity (vi) 
is fully 13^ times that found by the well-known velocity formula, V = 2 gh. 

It seems reasonable to assume that a like pressure drop is necessary to 
impart initial velocity within the heating main from a boiler or steam drum, 
as contrasted with the exhaust of an engine, reducing valve, etc. 

Table 11-1 gives one and one-half times the pressure drop or head 
(hi) in decimals of a pound and fractional ounces per square inch, based on 
the above assumption. 

Table 11-1. Velocity Head at Entrance of Mains 

In decimals of one pound and at fractional ounces per square inch. For 
various velocities as of initial density due to absolute initial steam pressures 
from 15 to 20 pounds per square inch. 

Table 11-1. Absolute Pressure 



Pressure 


Pressure Drop 

in Parts of 

Pound per 

Sq.In. 


15 


16 


17 


18 


19 


20 


Ounces 
per Sq. In. 




VELOCITY IN FEET 


PER MINUTE 




p. 

3 

6 

12 


ill 

t 

ft 


.0134 
.0234 
.046875 
.093750 

.187500 

.3750 

.750 


2578 
3684 
5157 
7368 

10315 
14736 
20630 


2507 
3582 
5014 
7164 

10029 
14328 
20059 


2437 
3480 
4874 
6960 

9744 
13920 
19488 


2373 
3390 
4746 
6780 

9492 
13560 
18984 


2314 
3304 
4628 
6611 

9256 
13224 
18513 


2238 
3131 
4476 
6395 

8953 
12791 
17907 



Friction in Run: Steam having attained initial velocity at the entrance 
of the main by a pressure drop (pi — P2), will require a further drop (pj — ps) 
to overcome friction. 



11—1 



Various formulae which agree quite closely as to larger sizes of pipe are 
in use; some of these do not appear to take in consideration the increased 
proportion of frictional surface to volume in the smaller sizes. 

The formula here advanced has been found in practice to give satis- 
factory results. 



1 . 
W = 60 C V (P= ~ ?'■* *^' 



V- 



in which 



L plus 50 



Formula 11-1 



W = pounds per hour. ^ = density in pounds per cubic foot, 

d = inches internal diameter. L = length in feet. C = a variable de- 
pendent on diameter, and is as follows for various sizes of pipe. 



Size of pipe 
Value of C 


I IH I'A 2 23^ 3 
20 30 36 45 52 55 


31^ 4 5 6 
57 58 59 60 


7 
60.5 


Size of pipe 
Value of C 


8 9 10 12 
61.0 61.5 62.0 62.2 


14 16 18 
62.4 62.6 62.8 


20 
63 



The following table has been computed from the formula 

Table 11-2. Weight of steam flowing uniformly in one hour through straight 

level pipes 1000 feet long, with a loss of 1 lb. per sq. in. from given initial 

velocity within inlet end 

No allowance is made for drop due to initial velocity or condensation 
losses in run. 

1 = nominal size of pipe in inches. 

2 = actual diameter of pipe in inches. 

3 = linear feet per cubic foot internal volume. 

4 = actual outside diameter of pipe in inches. 

5 = actual inside area of pipe in square inches. 

6 = length of straight pipe per square foot of external surface. 

7 = square feet of external surface per linear foot of pipe. 

8 = value of (Actual Diameter) - expressing the square root of the fifth 

power of actual diameter. 

9 = value of C in the equation. 

P = absolute pressure. 

S = cubic feet per pound of steam as of initial density. 

^ = pounds per cubic foot of steam as of initial density. 

L = latent heat of the steam. 

Lbs. = pounds of steam flowing through pipe per hour. 

^f; = thousands of B.t.u. contained in entering steam. 

B.t.u. ° 

V = velocity in feet per minute, as of initial density. 

From Table 11-2, pressure drop for other lengths of run, other weights 

of steam or both may be estimated. 

11—2 



Table 11-2. 







B 


0) 

^» 

II 

— c: 

3 ■ 


h 

-en 

ss 

in 


3 aa 
iJtnto 


d-.g 

Ui-I 


3 

l. 

o6 


1 
= 1 


P 


15 


16 


17 


18 


19 


20 


in 


« 




S 


26.27 


24.79 


23.38 


22.16 


21.07 


20.08 




II i"S 

N no 


1 

V 


.03806 


,04042 


.04277 


.04512 


.04746 


.04980 


S 


L 


969.7 


967.6 


965.6 


963.7 


961.8 


960. 


1" 


1.049167.5 


1.315 


.86 


2.9 


.345 


1.13 


20. 


Lb. 

lOOOB.t.u. 

V 


8.16 
7.91 
600. 


8.38 
8.09 
580. 


8.64 
8.32 
564. 


8.88 
8.55 
549. 


9.12 
8.76 
537. 


9.34 
8.86 
524. 


IK" 


i 
1.3S ; 9G.1 

) 


1.66 


1.5 


2.3 


.434 


2.235 


30. 


Lb. 

1000 B.t.u. 

V 


24.2 
23.53 
1015. 


25.1 
25.01 
987. 


25,7 
25.66 
958. 


26.4 
26.41 
936. 


27. 
27.07 
922. 


27.7 
27.73 
891. 


1^" 


1.61 


70.6 


1.9 


2,04 


2.01 


.497 


3.28 


36. 


Lb. 

lOOOB.t.u. 

V 


42.7 
41.4 
1320. 


43.9 
42.4 
1280, 


45.2 
43.6 
1240. 


46.4 
44.71 
1210. 


47,7 
45,87 
1180. 


48.8 
46.84 
1150. 


2" 


2.067 


42.9 


2.375 


3.36 


1.61 


.621 


6.13 


45. 


Lb. 

lOOOB.t.u. 

V 


99.8 
96.71 
1870. 


102,4 
99.3 
1815, 


105.5 
101.9 
1765. 


108.3 
104.4 
1715. 


111.2 
106.9 
1680. 


114.0 
109.5 
1640. 


2M" 


2.469 


.30.15 


2.875 


4.78 


1.33 


.751 


9.58 


52. 


Lb. 

lOOOB.t.u. 

V 


180.4 
174.5 
2380. 


185. 
178,8 
2.300. 


191. 

184,2 

2240, . 


196, 

188,8 
2180, 


201. 
193.3 
2125. 


206. 
197.7 
2080. 


3" 


3.068 


19.5 


3.5 


7.39 


1.09 


.991 


16.47 


55. 


Lb. 

1000 B.t.u. 

V 


327.6 
317. 
2790. 


336.5 
325. 
2710. 


347, 

335, 

2640, 


356, 
344, 
2550, 


365. 

351. 

2490. 


374. 
3.59.5 
2440. 


3H" 


3.54S 


14.58 


4. 


9. 89 


,955 


1.046 


23.7 


57. 


Lb. 

lOOOB.t.u. 

V 


488.4 
473. 
3120. 


502. 
485. 
3030. 


516. 
498. 
2930. 


531. 
511.7 
2860. 


545. 
524.1 
2790, 


55.9 
5.36.6 
2730. 


4" 


4.026 


11.3 


4.5 


12.73 


.849 


1.177 


32.53 


£8. 


Lb. 

1000 B.t.u. 

V 


681.6 
660.1 
3380. 


702. 
678. 
3280. 


722. 

697. 

3180. 


742. 
715. 
3090. 


761, 
731,9 
3020, 


781. 
749.7 
2950. 


5" 


5.047 


7.22 


5.563 


19.99 


.686 


1.457 


57.17 


£9. 


Lb. 

1000 B.t.u. 

V 


1218. 
1179. 
3840. 


1250. 
1207. 
3730. 


1288. 
1242. 
3620. 


1324. 
1275. 
3530. 


1358. 
1304. 
3450. 


1393. 
1337. 
3330. 


6" 


6.065 4.99 


6.625 


28.89 


.577 


1.733 


90.6 


60. 


Lb. 

1000 B.t.u. 

V 


1968. 
1906. 
4300. 


2020. 
1954. 
4160. 


2080. 
2006. 
4040. 


2136. 
2055. 
3940, 


2190. 
2105. 
3850. 


2245. 
2155. 
3750. 


7" 


7.023 


3.72 


7.625 


38.74 


.501 


2. 


130.7 


fO.5 


Lb. 

1000 B.t.u. 

V 


2864. 
2770. 
4660. 


2940. 
2841. 
4520. 


3026. 
2920. 
4380. 


3110, 
2992, 
4270. 


3190. 
3067. 
4170. 


3270. 
3139. 
4070. 


8" 


7.981 


2.88 


8.625 


50.02 


.443 


2.257 


180. 


61. 


Lb. 

1000 B.t.u. 

V 


3978. 
3855. 
5010. 


4080. 
3948. 
4850. 


4200. 
4050. 
4710. 


4320. 
4160. 
4590. 


4430. 
4260. 
4490. 


4.550. 
4368. 
4340. 


9" 


8.941 


2.29 


9.625 


62.72 


.397 


2.58 


239. 


61.5 


Lb. 

1000 B.t.u. 

V 


5320. 
5157. 
5240. 


5470. 
5293. 
5175. 


5630. 
5430. 
5020. 


5780. 
5570. 
4890. 


5930. 
5700. 
4770. 


6080. 
5837. 
4660. 


10" 


10.02 ' 1.83 


10.75 


78.82 


.355 


2.82 


317.7 


62. 


Lb. 

lOOOB.t.u. 

V 


7116. 
6900. 
5703. 


7320. 
7083. 
5530. 


7540. 
7270. 
5370. 


7750. 
7460. 
5240. 


7930. 
7625. 
5110. 


8150. 
7824. 
5000. 


12" 


12. 1.27 


12.75 


113.1 


.299 


3.3 


498.8 


62.2 


Lb. 

lOOOB.t.u. 

V 


11220. 
10870. 
6240. 


11500. 
11100. 
6040. 


11840. 
11410. 
5860. 


12180. 
11710. 
5710. 


12500. 
12010. 
5580. 


12810. 
12290. 
5460. 


14" 


14.25 


.904 


15. 


159.5 


.255 


3.90 


766.5 


62.4 


Lb. 

1000 B.t.u 

V 


17250. 
16720. 
6847. 


17800. 
17220. 
6640. 


18300. 
17650 . 
6460. 


18780. 
18070 . 
6270. 


19270. 
18520. 
6120. 


19700. 
18910. 
6960. 


16" 


15.5 


.765 


16. 


188.3 


.239 


4.16 


945.9 


62.6 


Lb. 

1000 B.t.u 

V 


21480. 

20S30 , 

7200. 


22080 . 
21320. 
6970. 


22700. 
21900. 
6760. 


23350. 
22470. 
6590. 


23900. 
23010. 
6440. 


24550. 
23.570. 
6280. 


18" 


17.5 


.601 


18. 


240. 


.212 


4.71 


1281. 


62.8 


Lb. 

1000 B.t.u 

V 


29100. 
2S220 . 
7660. 


29SG0 . 

28860 . 

7410, 


.30750. 
29670 . 
7200. 


31600 . 
30400. 
7020. 


32400 . 
31100. 
6830 . 


33300 . 

31970. 

6700. 


20" 


19.5 


.483 


20. 


298. 


.191 


5.23 


1679. 


63. 


Lb. 

1000 B.t.u 

V 


38280. 
,37100. 
8100. 


39350 , 
38080, 
7850, 


40-500 . 
39100. 
7630. 


41600. 

40100 . 

7420. 


42700 . 

41000, 

7250. 


43800. 

42050. 

7080. 



11—3 



For a given weight of steam other than tabular for any given size of 
pipe, the pressure drop per 1000 feet corresponding to the given weight is 
the square root of the quotient obtained by dividing tlie given weight by 
the tabular weight. 





1 


















^ 




1 


'~ 






























B.t. u 


pe 


rH 


r, per 


Sq. 


Ft 


w 


th 


Sat'urafedl 


/ 
































Ste]am 


at|T, 


abqve 


Stil) A 


rat T 


Vert. 


Ord. / 






























/ 




T,- 


T^ 


H 


jriz 





rd, 


B. 


;. u 


per \ 


r. in Still 1/ 




























/ 


/ 




Air 
























/ 


' 


























/ 


' 






























/ 


























/ 


' 






























/ 


/ 
























/ 


































/ 
























/ 




































/ 






















/ 


























































/ 


























































/ 






































/ 




















/ 








































/ 


















/ 








































1 


^ 
















/ 


























































/ 












































1 














/ 












































l/ 














/ 


/ 










































_§ 














/ 


/ 












































^/ 














/ 












































^/ 










•■^J 


/ 














































■^y 


' 








r« 


f^ 
















































7 










^^/ 


J 
















































/ 








."^^^ 


{ 
























































<= 


y 


























































/ 


















































, 








/ 


/ 


















































/ 








/ 










































^ 










/ 






/ 








































^ 


^ 
















t 


/ 


































^ 


--' 






















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^ 


^ 
























/ 




























^ 




^ 




























/ 




















%-^ 


.^'^ 


^ 


































/ 






















--' 


































/ 




















^ 








































/ 














--■ 


^ 










































/ 


























































y 


/ 








^ 
















































/ 


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// 


1 




y' 






















































1/^^ 



























































10 20 30 40 50 60 70 80 90 100 120 140 160 180 200 220 240 260 
B, t. u, Radiation per Hour per Sq. Ft. of Pipe Bare and Covered 



300° 
960 V. 



200° 
540 V. 



280 300 



Fig. 11-1. Heat Transmission in B.t.u. per hour per square foot of Bare and 

Covered Pipe 



11- 



This new pressxire drop for 1000 feet increases or decreases in percentage 
as new run is more or less than 1000. 

Condensation Loss: Through the entire length of run, there is a further 
loss of pressure, due to radiation and condensation. This loss is least in 
well covered mains with still air, at high temperature. Condensation in 
long runs of small pipe frequently causes the greatest loss of weight and oc- 
casions large pressure drop. 

The following example is given to call attention to what is likely to 
happen if tabular steam values, in straight runs, be used to size mains sup- 
plying radiation through long runs of small pipe, even if the mains are well 
insulated. From Table 11-2 it will be seen that a 13^2 in. pipe with a friction 
loss of 1/10 pound per 100 feet and an initial pressure of 16 lb. absolute will 
convey steam at an hourly rate of 43.9 lb. or 42,400 B.t.u. per hour. 

By inspection of Figure 11-1, we find that if the difference in tempera- 
ture between steam in the pipe and air surrounding it is 150 deg. fahr. 
and the pipe has a high-grade insulation, there is transmitted through that 
covering about 25 B.t.u. per lineal foot (3^2 sq. ft.), or 25,000 B.t.u. per hour 
for 1000 feet run. Therefore, about 60 per cent of the entering steam is 
condensed, and the balance flows at so low a pressure as to be of little value 
except under high vacuum. 

For various differences between temperature of steam in the pipe and 
temperature of the surrounding space. 

Effect of Deflection, Contraction and Expansion: Mains are seldom 
straight cylindrical pipe from end to end. Normally there are elbows, 
valves, branch outlets, reductions in size, separators, expansion joints, etc., 
each adding to frictional resistance and causing pressure drop. 

Although not technically accurate, it has been found convenient in 
estimating, to express these resistances in units of the additional length of 
run of straight pipe that would produce an equal effect. Table 11-3, which 

Table 11-3. Equivalent Resistance of Straight Pipe to Be Added to Run 

for Fittings 







Long Sweep 


Medium 


Standard 










Size of Pipe 


Gate Valve 


Run of 


Sweep Ell 
Reduced 


EU 
Much 


Angle 


Short 


Side 
Outlet 


Globe 


in Inches 




Standard 
Tee 


Run of 
Tee 


Reduced 
Tee 


Valve 


Bend 


Tee 


Valve 








LENGTH IN 


FEET TO 


BE ADDED 


TO RUN 






2 


2 


3 


4 


5 


9 


11 


17 


19 


2y2 


3 


4 


5 


7 


12 


15 


21 


26 


3 


3 


5 


6 


10 


16 


19 


27 


33 


3}4 


4 


6 


8 


12 


19 


22 


32 


39 


4 


5 


7 


9 


14 


22 


24 


36 


45 


5 


7 


9 


11 


18 


27 


30 


44 


58 


6 ' 


9 


11 


14 


22 


32 


36 


51 


70 


7 


10 


13 


17 


26 


37 


41 


56 


82 


8 


12 


15 


20 


31 


42 


47 


63 


94 


9 


13 


17 


22 


35 


47 


52 


68 


104 


10 


15 


20 


24 


39 


52 


57 


76 


117 


12 


18 


24 


30 


47 


62 


68 


91 


140 


14 


20 


26 


33 


53 


71 


79 


105 


160 



11—5 



is believed to be conservative and likely to produce results well within the 
tolerance necessary in so complicated a subject, is figured upon this basis. 

This table is not claimed to be absolutely accurate, as fittings of dif- 
ferent manufacturers vary in resistance in similar sizes and similar fittings 
vary in percentage of resistance. No very careful tests covering the entire 
range of flow of water, air and steam are available for data, but those that 
do exist have been studied and referred to in making up this table. 

B. Pressure Drop: The necessity for pressure drop to create flow in 
heating systems has been explained in preceding pages. Modulation and 
vacuum heating systems differ in degree of this pressure drop rather than 
in principle. 

Pressure Drop in Vacuum Systems:* The reason for employing a vacuum 
system rather than a modulation system lies in the greater total drop than 
is obtainable from a given initial pressure P above atmospheric to a terminal 
pressure p which is less than atmospheric, thereby obtaining circulation 
through greater resistEuice due to long pipe runs and lack of grade for gravity 
flow of condensation. 

Lr we"ing the terminal pressure p by mechanical exhaustion in return 
mains (the vacuum system) provides for greater pressure drops through each 
of the series of resistance. 

In good vacuum system practice, the total drop between source of sup- 
ply through the inlet valve to the farthest radiator on the system should be 
that between available initial and atmospheric pressure, so that normally 
the pressure in the radiator will be at or very slightly below that of the at- 
mosphere. The pressure drop p4 of the return trap may usually be twice to 
three times that permissible in a well designed modulation system. The 
drop Pa in the vacuum return lines, if graded in direction of flow, may equal 
that in the supply mains of the system under consideration, and if it be neces- 
sary to elevate the condensation at one or more vertical lifts in order to ob- 
tain horizontal grade toward the vacuum pump, this (within, Umits of tem- 
perature of condensation) may be obtained by increasing the displacement 
of air and vapor by the pump. In systems where the high vacuum neces- 
sary to lift the condensation at one or more points, would occasion a need- 
lessly high vacuum in that portion of return system which has a gravity 
flow, the degree of vacuum may be reduced by means of special apparatus 
incorporated in the Webster Hylo Vacuum System which provides for con- 
tinuous discharge of condensation and also for a reduction of degree of 
vacuum between the inlet and outlet of the apparatus. (See Chapter 23, 
page 00, for description.) 

In general, owing to greater pressure drop, a vacuum system will not 
require as large mains, branches to, and inlet valves of radiation as needed 
for a modulation system. Likewise, the radiator traps and return mains 
may be smaller for similar sized units of radiation provided radiator traps of 
high efficiency are properly installed to prevent leakage of steam to return lines. 

It i^, as previously stated, good vacuum system practice to proportion 
mains between source and radiation for the pressure difference between 
initial and atmospheric as further described in this chapter. 

* For illustration of symbols see Figure 11-2. 
11—6 



Return traps should be proportioned for between y^ and 1 pound pres- 
sure difference. 

Return mains should be proportioned relatively to the steam mains 
selected for equal duty by the table of comparative sizes (Table 11-4), 
allowing additional areas, however, when there is probability of high tempera- 
ture in the outlet end of returns, due to steam leakage of return traps or 
lack of vapor condensation occasioned by thoroughly insulated mains re- 
taining the heat in the water passing through the radiator traps. 

At least one size larger return main should be used where high vacuum 
for lifts increases volume of vapors and ga'ies to be removed. 

Such degree of partial vacuum should be carried by properly propor- 
tioned pump displacement as to cause a partial vacuum equal to the selected 
pressure difference (P4) through the most remote return traps on the system. 
In proportioning pump displacement for vacuum systems, the most complex 
problem is that of proper allowance for the amount of vapor and air. Pres- 
sure below atmosphere in any part of the system is liable to induce invisible 
air leaks. For full efficiency of radiation the temperature of condensation 
passing through return traps must be close to that due to the steam pressure 
in the radiator. 

This hot w ater flowing into the lower pressure in return lines partially 
flashes into vapor of high specific volume, as may be determined by inspec- 
tion of the re-evaporation chart, Figm-e 21-00, Chapter 21, and referring 
the percentage there found to the volume occupied by the ascertained 
weight when at the pressure in the return pipe. Some of this vapor will be 
condensed on the way to the pump, the amount depending on whether or 
not returns are insulated and on the efficiency of that insulation. It must 
also be borne in mind that when the temperature of water of condensation 
exceeds that of vapor at the vacuum pressure, a portion of this water will 
flash into vapor occupying many hundreds of times its volume as water and 
practically impossible of mechanical displacement by a pump. 

Inleakage of air through even minute imperfections in piping causes an 
increase of volume to be handled proportionately as the absolute tempera- 
ture of the air at inleak is to the absolute temperature in the return system, 

Table 11-4. Normal Relation of Return Mains and Risers to Supply Mains 
Caring for Equal Amounts of Steam in Vacuum Systems 

Gravity drip vertical outlet at heel of risers 2J4 ^nd under less 
than 12 stories high y^ in. Over 12 stories or over 2J^ riser 1 in. 
Vertical outlet increasing in horizontal rim to IJ^. 
Horizontal gravity drips Number of ^ or 1 in. outlets which 

graded at least J^ in. in may be carried on one horizontal 

10 feet are usually capa- run when graded J4 in. in 10 feet, 

ble of caring for the num- provided radiation on steam riser 

ber of ^ or 1 in. outlets does not drain as in one pipe 

as follows : system. 

Size 
Horizontal 

IM 
W% 
2 

3 
11—7 



Horizontal 


Horizontal 


Vertical 


Supply Main 


Return 


Return 


1J4 and less 


% 


M 


l>^and2 


1 


M 


2J^ 


Wa 


1 


3 and 3>^ 


W2 


Ik' 


4, V/i and 5 


9 


iM 


6 and 7 


W2 


9 


8 and 9 


3 


W% . 


10 


Wi 


3 


12 


4 


3^ 


14 and 15 


4M 


4 


16 and 17 


5 


4,1^ 


18 and 20 


6 


.5 



No. of Yi" 


No. of 1" 


Outlets 


Outlets 


12 


6 


18 


12 


30 


18 


60 


36 


100 


.-■jO 



plus expansion from that volume at atmospheric pressure to that of vacuum 
pressure. 

As explained in Chapter 14 on Vacuum Piunps, it is frequently possible 
to take advantage of some condensing medium such as cool air for ventila- 
tion, or water, for cooking and washing, boiler feed, etc., which must be 
warmed, and use this medium for cooling and condensing the air and vapor 
to decrease its volume on the way to the pump. 

The basic proportional sizes of retm-ns to mains recommended in the 
above discussion are given in Table 11-4.. 

, S upply VaWe 



Steam Riser^ 



Radiator 




WEBSTER 
RETURN TRAP 

'p WEBSTER 
* RETURN TRAP 



.Dry Relurii 



m 



giL 




«^ 



^Return Header 

Check Valve 



J=^ 



& 



Fig. 11-2. Diagram of Modulation System layout to Illustrate Pressure Drop 

Pressure Drop in Modulation Systems: The typical modulation system, 
as illustrated in Figure 11-2, when operating at normal rate, requires suffi- 
cient pressure against the valve piece of the check valve pi to cause it to 
open against the atmospheric pressiue. Representing atmospheric pressure 
as p and this excess pressure as pi the expressions p + pi = pressure at en- 
trance of check valve. 

To cause the air to flow from the vent trap through the vent valve 
orifice requires a pressure difference, which may be represented by p2, vary- 
ing with velocity of flow. Therefore, pressure in the vent trap becomes 
= p -|- pi + p2. To cause the air to flow from outlet of the radiator trap 
through return main to the vent trap, there must be another pressure 
difference, represented by ps, dependent on velocity of flow; also another 
pressure difference through orifice of radiator trap p^. Therefore, pressure 
Pb in the radiator at the time of air displacement by steam from the boiler 
must equal the sum of p4 + Ps + P2 + pi + p. Of these last expressions 
p is relatively constant with gauge at lb. The flow through the check valve 
pi is nearly constant, being mainly that pressure difference necessary to 

11—8 



overcome the gravity of the clapper and adhesion of wet surfaces of seat. 
The variable due to the volume of air passing is so slight, owing to low ve- 
locity, that it may usually be neglected. 

The range of pressure pi of a check valve suitable for a modulation sys- 
tem is from 1,20 to 1/12 lb. per sq. in. 

The pressure di'op through vent valve orifice ps is a variable — greatest 
during initial heating-up period when a large volume of cool air is expelled 
from the heating system, and least during normal heating when velocity 
is that slight amount due to entrained air in condensation passing from the 
radiation. Air-vent traps are rated on basis of flow of initial air in 40 min- 
utes in a system with 1/16 lb. per sq. in. differential pressure through the 
vent- trap valve. 

For less than rated capacity, either the time or pressure factor or both 
may be less ; for instance, with p2 constant, one-half the amount of radiation 
would require one-half the time period. 

The pressure drop in the return main ps is also a variable: greatest 
during initial heating, and dependent on length of run and maximum 
velocity. In a well-proportioned system, ps should never exceed 1/20 lb. 
per sq. in. differential between the farthest radiator trap and the vent trap, 
and during normal heating it is so slight as to be almost negligible. 

The pressure drop through a radiator trap p* is also a variable, least 
and almost negligible during initial expulsion of air from radiation, at which 
time the trap-valve orifice is wide open. As the radiator warms up and con- 
densation flows through trap orifice with the last of the contained air, p4 
gradually becomes greater. It becomes maximum when condensation, at 
or near steam temperature is flowing at the full rating of the return trap 
for a given p4 of 1/16 lb. per sq. in., which pressure has been selected from 
tabular ratings of return traps. It is good practice not to have p4 exceed 
1/16 lb. per sq. in. where it is advisable to carry less than 3^2 lb. pressure on 
the boiler and }/§ lb. where a pressure of 1 or 2 lb. CcUi be carried. 

Representing the pressure difference necessary for flow, initiaUy of air 
and subsequently of steam, from the radiator branch tlu"ough the inlet or 
modulation valve to the radiator, requires another variable pe, 1/32 lb. per 
sq. in. at full rating, least (in a properly designed Modulation Valve full 
open), during initial expulsion of air, and greatest when the valve is partly 
closed for modulation effect, at the selected rating of this valve, for a 
given p_6. 

P7 is usually assumed for a system of mains, risers, branches, and run- 
outs, designed from data on flow of steam in Main Table 11-0, to carry the 
maximum normal quantity of steam in a given time from the main heat pipe 
near the boiler to the inlet valve of farthest radiator, with this pressure 
drop Pt. 

The quantity of steam assumed in the preceding paragraph, carried 
tlirough the selected main heat pipe close to boiler, involves a velocity con- 
sequent on the area of pipe and volume flowing in unit time. To impart 
this velocity to the steam from condition of practically quiet in the steam 
space of the boiler, and to offset the resistance of the orifice, or the reduction 
in effective area, another pressure difference ps is required. This pressure 

11—9 



difference or velocity head may edso be ascertained from inspection of 
Table 11-1. "Velocity Head" for the given main heat pipe (selected 
under p?) delivering steam at maximum normal quantity, for the heating 
system under consideration. 

It follows from consideration of the above that the pressure in the boiler P 
at time of maximum normal heating effect must be the sum of p + pi + p2 
etc., including p^ as follows: 
p constant at atmospheric pressure, 
pi at least intermittent at that time. 
P2 negligible at that time. 

ps negligible at that time if return has proper grade. 
p4 tabular if full rated value in radiation is on furthest unit, 
ps pressure drop in radiator, negligible at that time, 
pe tabular if full rated value in radiation is on farthest unit, 
p? from assumption in design from flow of steam in main. Table 11-2 
ps that required for velocity head under above assumption. Table 11-1 

The heating-up period will vary in accordance with initial pressure in 
the source of steam supply. Usually some time is required to raise steam to 
the normal pressure P, and during that time air will be expelled and steam 
flow into the radiation at varying rates due to the increasing pressure through 
the increasing resistance of pi -j- ps. If steam is constantly supplied during 
the heating-up period at pressure P (as might be the case when a central 
plant is the steam source), the condensation rate in the radiation due to 
absorption of heat by the metal will be as far in excess of normal as the 
sum of maximum pi + p2 + ps + an intermediate p4., deducted from 
P — p, will produce a pressure difference (pa) to cause initial velocity and 
flow tlu'ough mains at a rate substantially proportional as pd is to p?, provided 
initial velocity equal to ps has been previously imparted to the steam within 
the entrance of the main. 

The intermediate p4 referred to in the above paragraph is caused by 
the partial extension of the thermostatically moved valve piece in the return 
trap, from full open and minimum resistance when chiUed condensation 
commences to pass, to nearly closed and full resistance, when the radiator 
is completely filled to the return trap with steam at a temperature corres- 
ponding with its pressure. 

Modulation systems when operated at less than normal condensation 
may continuously circulate at pressure materially lower than the normal 
P, or may be intermittently operated at a pressure less than p, provided the 
air has first been expelled by a higher operating pressure. Under such 
conditions, however, the system will gradually become air-bound and cease 
to circulate. 

In designing modulation systems, all gravity drip points should be pro- 
vided with a hydraulic head (Hi) of at least 23^ feet for each pound per 
square inch of p? + p, -|- frictional resistance in run of gravity drip and re- 
sistance of check valve between gravity drip and boiler when the boiler is 
•generating ste£un at its full capacity to supply cold radiation. 

If the gravity drip be taken from radiation located below the dry re- 
tm-n, with thermostatic air vent up to the dry return, then the resistance of 

11—10 



any additional branch main, radiator, valve and check valve on gravity drip, 
must be added to p? + pe, etc., given above, to determine whether H2 is 
sufficient. 

The hydrauUc head in inches of water on the check valves will vary 
with the make, weight and angle of the clapper and the size of pipe tapping. 
This head is seldom less than 3 inches with the clapper at an angle of 10 
degrees from vertical and may run up to 18 inches and higher with vertical- 
lift valve pieces. 

In instaUing radiation with gravity drip for condensation as above, it is 
important that the branch connections and valve to such radiation have 
sufficient free area when in use, to cause little or no reduction in pressure in 
the radiator, from that in the main. A partially closed inlet valve might 
cause such a reduction in pressure, when added to the other resistances, that 
there w^uld not rema'n sufficient total pressure in the radiator, when added 
to the available H2, to overcome the pressure P plus the check valve resist- 
ance in gravity drip; in consequence of this, condensation would build up 
in the column H2, seal the radiator outlet and finally cause the radiator to 
become water-logged, possibly draining at a partial condensation rate, 
through the air vent into the dry return line. 

The closing level of the air-vent trap, should be located at such a height 
above the water line of the boiler that a hydraulic column fully equal to the 
resistance c f its check valve and drain pipe plus normal P is produced. 

This, however, is not as important as to have Hi and H2 ample. An 
air pressure will accumulate in this vent trap due to closing of the vent out- 
let, when Column H is not sufficient to overcome resistance of drip line and 
excess P plus pressure in boiler. This air pressure will continue to build 
up with vent closed, until the built-up pressure with the assistance of 
Column H overcomes the resistance of the boiler pressure. Then Column 
H will fall, the air vent will open and allow escape of some air, thereby re- 
lieving pa^^t ^ f pressure in the vent trap. Column H will again rise, closing the 
air vent, and this cycle will be repeated. When intermittent venting is repeated 
for a sufficient length of time under excess pressure P without admitting raw 
feed water contain ng gases, all the air will be expelled from the radiation. 

Such a system will continue indefinitely to circulate, due to a pressure 
diffen nee which will be fully equal to that of its normal H; that is, the pres- 
sure in the vent trap will be less than the pressure in the boiler, by an amount 
equal to an hydraulic column of height H less the resistance of the check 
valve en the drip of this column. 

The only difficulty with excess pressures P in modulation systems, de- 
signed for pressure P and open vent at head H, occurs from rapid raising 
of steam and generation of excess P before the initial air has been expelled. 
Under such conditions complete circulation will not be obtained as rapidly 
as if steam had been raised more slowly. 

As stated in the discussion of "Pressure Drop in Vacuum Systems," 
the retu n mains should be proportioned relatively to the steam mains 
selected for equal duty. This principle applies also to modulation systems. 

Th ' ba ic proportional sizes of returns to supply mains recommended 
are given in Table 11-5: 

11—11 



Table 11-5. Relative Proportions of Steam Supply and Return Mains in 
Modulation Systems 



Supply Main 



Dry Return Main 



Return Riser 



1 

VA and 2 
2}^ 




'A 
% 
1 


M 


3and3K 
4 

4)^ and 5 
6 




1}^ 

2 
2M 


VA 


7 and 8 
9 and 10 
12 


3 and Z}4 

4 and 4}^ 

5 


3 
4 


2 

2 

2^ 



C. Sizing of Piping: The use 
of the foregoing tables in sizing 
piping may best be explained by 
fjll owing examples. 

Vacuum System: Assuming a 
central steam generating plant for 
a group of buildings as shown in 
Figure 11-3. 

In the problem here presented 
are a boiler house and three de- 
tached buildings A, B and C, 
connected by a system of weU- 
covered mains in a tunnel. Through these 
ma^ns it is desired to convey 6000 lb. of 
steam to building A, 5000 lb. to building 
B, and 3000 lb. to building C, per hour, with 
a pressure drop from 16 lb. absolute in the 
boilers to or near atmospheric pressure just 
beyond the main valve in each building. 

A good grade of covering, still air at 
about 70 degrees and proper drainage are 
assumed. 

1. We find the total steam re- 
quirement per hour of build- 
ings A, B and C to be ... . 

2. The longest run of the main 
is to building C, which with- 
out allowances is 

3. By referring to Table 11-2, 
we find under the Column 
of 16 lb. absolute that for a 

1000 ft. run and 1 lb. drop 
in pressure a 14-in. main 
will convey 17,800 lb. 

11—12 



3" 



r 



3'^ 



T^^ 



4M 



^y^^, 



14,000 lb. 



880 ft. 



1*-^ 



K. 



-8"- 7" Trial Size 
-12"- 10" Trial Size 



AT- 10" Trial Size 
10" 200' 



'ts' 



14" 



3/2". 



20' 



16tf 
Boiler 



4. Length of trunk main from boiler house to first branch 

main 425 ft. 

5. Referring to Table 11-3, we find the allowance for a 14-in. 
angle valve to be 71 and for a 14-in. flanged ell 53 — Total 

for 1 angle valve and 6 ells = 71 plus (6 x 53) =........ 389 ft. 

6. Trunk run with allowances, 425 plus 389 = 814 ft. 

7. Branch main to building A must carry 6000 lb. 

8. From Table 11-2 we find under column of 16 lb. absolute 
pressure that for a 1000 ft. run and 1 lb. drop in pressure 

a 10-in. ma n will convey 7320 lb. 

9. Length of branch run to A 255 ft. 

10. Branch A allowances, 1 outlet, 2 ells and 1 globe valve, 

which according to Table 11-3 = 53 plus (2 X 39 )plus 117 . 248 ft. 

11. Total branch run A 255 plus 248 503 ft. 

12. Beyt nd the fust branch B and C require 5000 plus 3000 lb. 8000 lb. 

13. From Table 11-2 we find that a 12-in. main will carry 
11,500 lb. and a 10-in. will carry 7320 lb. For a trial we 

take the latter 7320 lb. 

14. Length of 10-in. run net 200 ft. 

15. Allowance for 1 14 X 10 run-reducing tee from Table 11-3 24 ft. 

16. Total run 200 plus 24. .... 224 ft. 

17. From 10-in. tee inlet, building B — requires net. 5000 lb. 

18. From Table 11-2, we find that under the same condition 

as above a 9-in. main will carry 5470 lb. 

19. Net run of branch main to B 155 ft. 

20. Allowance for 2 — 9-in. ells and 1 globe valve from Table 

11-3 = (2X35) plus 104 174 ft. 

21. Total 9-in. run of branch to B = 155 plus 174 329 ft. 

22. Steam requirement of building B 3000 lb. 

23. From Table 11-2, we find that under conditions as above a 

7-in. main will carry 2940 lb. 

24. Net run of 7-in. main to building C 255 ft. 

25. Allowance for 1 reduction, 3 ells and 1 globe valve from 

Table 11-3, 17 plus (3X 26) plus 80 177 ft. 

26. Total run of 7-in. main, 255 plus 177 432 ft. 

To determine the condensation loss in the mains we convert the length 

of the runs to square feet of external surface from Column 6, Table 11-2, as 
follows: ^25 

27. Line 14-in. pipe— ^^ = 1660 sq. ft. 

255 

28. Line 10-in. pipe-|^ = 718 sq. ft. 

200 

29. Line 10-in. pipe^^ = 563 sq. ft. 

30. Line 9-in. pipe-^lf = 387 sq. ft. 

.597 

255 

31. Line 7-in. pipe ^ = 510 sq. ft. 

11—13 



32. Tjtal external surface 3838 sq. ft. 

33. Add 5% for fittings to the above, which w!ll make the total 
external surface 4030 sq. ft. Referr.ng to Figure 11-1, 
we find from the given condition of 140 degrees temper- 
ature difference (212° — 72°) that with thj assumed good 
quality covering we will have a heat emission of 50 B.t.u. 
per sq. ft. of external surface, or a total Ik at emis-iijn cf 

4030 X 50 201,500 B.t.u. 

34. Each pound of steam containing approximat ly 970 B.t.u. 

in latent heat, the 190,450 B.t.u. represents " „ ' — 208 lb. 

Allotting this total condensation loss in pounds to each cf the sepa ate 
runs we have 

for the 14-in. main line 90 lb. 

for the 10-in. main line 40 lb. 

for the 10-in. main line 30 lb. 

for the 9-in. main line 20 lb. 

for the 7-in. main hne 28 lb. 

35. To the line loss add the requirements of buildings A, B and 

G 14,000 lb. 

36. Total steam requirements 14,208 lb. 

37. We find in Table 11-2 that the steam-carrying capacity of 
a 14-in. main 1000 feet long, with steam at 16 lb. absolute 
and a drop in pressure of 1 lb., is 17,800 lb. per hr. The 
length of run in our problem and also the quantity of steam 
to be supplied are smaller and the pressure drop is also 
consequently reduced. 

The steam required, 14,205 lb. per hr., is 80% of the capac- 

ity, 17,800 lb. per hr. [yf^^) = -80 

Trunk run with allowances 814 ft. divided 1000 (the basic 

run) = .814 of the length for 1 lb. drop 

Drop in trunk main = S^80~X .814 = .89 X .814 = ... . 0.724 lb. 

38. Prajjm'e drop to A in the 10-in. pipe 

FJl jwlng the same line of reasoning as to the relation of 
st^am requirement in percentage of capacity and length of 
Tun in the percentage of basic run, we obtain a pressure to 
A (required 6000 lb. plus 40 lb. condensation bss) 
6000 + 40 „,. 
7320 = -^^^ 
Length of run, 503 divided by 1000 = .503 of basic 

length. 

Drop of pressure to A = V^824 X .503 = .905 X .503 , . .455 lb. 

39. Total drop to building A, including drop in trunk main 

= .455 plus .72 1.175 lb. 

11—14 



40. We arrive at the actual pressure drop to B and C in the 
same manner: 

Capacity of 10-in. main, 7320 lb. 

Steam requirement in B and C, including condensation 

losses = 8000 + 30 + 20 + 28 = 8078 lb. 

^« = 1.10 
7320 

Length of run, 225 ft. = .225 of basic run 

Pressure drop in 10-in. line VTTx .224 = 1.05 X. 224 = .235 lb. 

41. Pressure drop to B in the 9-in. line becomes 

^^^5470 "^ ^ ^0 ^'' ^~^^ ^ -^^^ " -^^ ^ -^^^ " ^^^ ^*^- 

42. Pressiu"e drop to C is obtained by the same procedure as ex- 
plained above and becomes 

^^^2^940 ^^ ^ ^ °^ ^^^ ^ -^^^ " ^-^^^ ^ -"^^^ " • • • -^^^ ^^• 

in which 30 lb. condensation loss is added to the steam re- 
quirement in the building in the same manner as the con- 
densation losses which are added in the other calculations, 
and 

43. By referring to Table 11-2, we find S the cubic feet per 
pound of steam, which for 16 lbs. absolute is very nearly 
24.8. 

Converting the total steam required in pounds per hour 
to cubic feet per minute, we have 

14207X24.8 352.333 _„^.^ „^ 

TTT = — 77; — = 5872 cu. It. per mm. 

60 60 ^ 

By referring to Table 11-2, Column 3, we find the linear 
feet per cubic foot of volume, which for a 14-in. pipe is .904. 
Multiplying 5872 by .904 we obtain the velocity in ft. per 
min. of the steam in the 14-in. main, V = 5300 ft. 

44. We must now determine the pressure drop to impart initial 
velocity, and by referring to Table 11-1, we find for a 5300- 
ft.-per-minute velocity and 16-lb. absolute pressure a 

velocity head of very nearly 0.047 lb. 

45. The series drop to building B, therefore, is the sum of .72 -\- 

.047 = .767 + .235 + .316 = 1.318 lb. 

46. The series drop to building C becomes 

.767 + .235 + .438 = 1.440 lb. 

47. The series drop to building A is 1.175 + .047 1.222 lb. 

As stated at the beginning of our problem, it was desired to have a 
pressure drop from 16 lb. absolute to or near atmospheric pressiu-e in the 
buildings, and we find that the pressure drop to building C is slightly above 
the 1.3 lb. drop desired, which shows that the 10-in. main and the 7-in. main 
(which were assumed for trial) should be increased to 12 in. and 8 in. res- 
pectively. 

11— ir^ 



Based on the increased sizes, the pressure drops will be re-calculated. 

48. The pressure drops in trunk main and the series drop in the 
main to building A will be assumed to remain as given, as 
we wiU neglect the small increase in the pressure drop in 
the trunk main due to the slight increase in condensation 
losses in the 12-in. and 8-in. mains as compared with the 
losses in the 10-in. and 7-in. mains before considered. 

49. Length of 12-in. run to B and C 200 ft. 

Length of 8-in. run to C 255 ft. 

Exposed surface of 12-in. main = -^^^ = 670 sq. ft. 

Exposed surface of 8-in. main = " ^ = 570 sq. ft. 

The condensation loss in the 12-in. main wiU be 35 lb. 

and in the 8-in. main 32 lb. 

50. Net run of 12-in. main 200 ft. 

51. Allowance for 1 reducing tee 30 ft. 

52. Total run of 12-in. main 200 plus 30 230 ft. 

53. Steam requirement to B and C, 8000 lb., to which we add 
the condensation losses in the 12-in., the 9-in. and the 8- 

in. lines, or 35 + 20 + 32 + 8000 8087 lb. 

54. From Table 11-2 we find the capacity of a 12-in. main at 
16 lb. absolute through 1000 ft. of pipe, and with 1 pound 
drop in pressure, to be 11,500 lb., and on the basis of a total 
run of 12-in. main of 230 ft. we have a pressure drop in 

this line = J -^^ x .230 = V7703 X .230 .193 lb. 

1 1.1. ^0\)\j 

55. Net run of 8-in. main to building C 255 ft. 

56. Allowance for 1 reduction, 3 ells and 1 globe valve, from 

Table 11-3, 20 + (3X31) + 94 = 207 ft. 

57. Total run of 8-in. main, 255 + 207 462 ft. 

58. Steam requirement to building C, 3000 lb., to which we add 

the condensation loss of 32 lb. = 3032 lb. 

59. From Table 11-2, we find that the capacity of an 8-in. pipe 
with a pressure drop of 1 lb. in 1000 ft. of pipe is 4080 
lb., and consequently the pressure drop in 462 ft. of 8-in. 

pipe supplying 3032 lb. of steam is |^ X j^ = 

S~Ji X .429 = .85 X .462 = .393 lb. 

60. The series drop to building B now becomes the sum of 

.724 + .047 + .193 + .316 = 1.280 lb. 

as compared with the previous pressure drop of 1.318. 

61. Considering the changed series drop to building C, we find 
same to be 

.724 -t- .047 + .193 + .393 = 1.357 lb. 

As all of the pressure drops come so close to the maximum 
assumed drop of 1.3 lb., 14-in. trunk main, a 10-in. 

11—16 



branch to building A; 12-m. to B and C with a 9-in. line 
leading to B and 8-in. to building C, are the closest possible 
in commercial pipe sizes. 

Long computations such as above are required only in connection with 
extensive distributing systems where the cost of one size larger pipe be- 
comes important. 

For general use in sizing mains and branches of mains in buildings for 
radiation, separate tables based on 70 per cent of the values from Table 11-2 
will cover an ordinary amount of valves and fittings (if globe valves are 
excluded), and if used with discretion will prove sufficiently accurate. 

For couA^enience in laying out general work. Tables 11-6 to 11-9, based 
on these values, are computed and appended at the end of this chapter. 

The sizing of run-outs requires special consideration, however, and will 
be discussed in Chapter 12, on "Critical Flow of Steam." 

For sizing the return mains we refer to Table 11-4. Based on the sizes 
of steam supply mains as obtained in the foregoing example, we Eu-rive at 
the following conclusion: 

Return from Building C 3 in. 

Return from Building B 3 in. 

Connect the two 3-in. returns from buildings B and C into one 4-in., to 
which the return from building A, which is 33/^ in., connects, and increase 
the return at this point to 43^2 in. 

The 4,V2-in. return is continued full size to the boiler house. 

For sizing branch return mains and run-outs the same procedure is 
followed, that is, the size of the return is based on the size of supply selected 
for an equal duty. 

Modulation System: In sizing piping for modulation systems, long com- 
putations such as described under vacuum systems are not necessary. 
The Tables 11-6 to 11-9 appended at the end of this chapter are sufficiently 
accurate for ordinary conditions. 

The total quantity of steam to be supplied per hour at the time of maxi- 
mum normal heating effect being a known factor and the total maximum 
pressure drop in the heating system being determined for this period, the 
pressure drop in the supply main must be so chosen that the pressure to be 
carried on the boiler will exceed by a safe margin the sum total of resistances 
between the boiler and the outlet of the vent valve. 

For an illustration, assume a typical modulation system which requires 
500 lb. of steam per hour for maximum normal heating effect. The length 
of run is assumed to be 300 ft. and the boiler pressure is not to exceed J/2 
lb. gauge. 

To find the proper size of supply main to meet these conditions, the 
pressure drops from p to pe as described in the discussion of "Pressure Drop 
in Modulation Systems," must be determined, before the permissible pres- 
sure drop Pt in the supply main can be ascertained. 

During maximum normal heating effect we find the pressure drop from 
p to p 6 to be as follows: 

11—17 



p = constant at atmospheric pressure = 0.000 lb. gauge 

pi = pressure drop through vent check valve (intermittent 

at that period) = 1/20 lb. = 0.050 " 

p2 = pressure drop through vent valve orifice (negligible at 

that time) = 0.000 " 

Pa = pressure drop in return main is negligible if return has 

proper grade = 0.000 " 

p4 = pressure drop tlirough orifice of radiator trap, \\ hich for 
the given condition will be the maximum tabular value 

of 1/16 lb = 0.060 " 

P5 = pressure drop tlirough radiator is negligible at that 

time = 0.000 " " ' 

pe = pressure drop through radiator valve will be the maxi- 
mum tabular value for the given period — 1/32 lb. =0.031 " " 

Total drop p to ps = 0.141 " 

The pressure to be carried on the boiler = 3^ lb 0.500 " " 

Pressure drop p to pe = 0.141 " " 

D'fference of pressure available 0.359 " " 

Bearing in mind that in addition to the pressure drop p? in the supply 
main, we must consider also the pressure drop ps to impart initial velocity, 
we readily see that a pressm-e drop of i| lb. in the supply main would be 
unsafe and we, therefore, select the H lb. drop in the supply main p? as the 
basis for determining the size of pipe required. 

We find by referring to Table 11-6 that a 5 in. main is necessary to sup- 
ply 500 lb. of steam with 3^ lb. drop in pressure in a run of 300 ft. 

We now have to determine the head or pressure drop ps necessary to 
impart initial velocity to the steam. 

From Table 11-2, we find S, the cubic ft. per pound of steam at 15.3 
lb. absolute (assumed boiler pressure) is very nearly 26.27. 

Converting the total steam required in pounds per hour into cubic 
feet per minute 

500 X 26.27 13135 „,„„ _^„ ,. „ ^ 
^ = ^„ = 218.9, or, say, 219 cubic teet. 

By referring to Table 11-2, column 3, we find the linear feet per cubic 
foot V jlume, which for a 5 in. pipe is 7.22. 

Multiplying 219 by 7.22 we obtain the velocity in feet per minute of 
the steam to be 1582 ft. 

We now determine the pressure drop ps necessary to impart initial 
velocity and by referring to Table 11-1 we find for a 2500-ft velocity, a pres- 
sure drop of 0.0134 lb., which for a 1582-ft. velocity would be approximately 
0.008 lb. per sq. inch. 

The total pressure drop between the boiler and the outlet of the vent 
valve then becomes: 

Pressure drop p - Pe as stated before = 0.141 lb. gauge 

Pressure drop p? in main 3^ lb. = 0.125 " " 

Pressure drop ps to impart initial velocity = 0.008 " " 

Total pressure drop p — P= 0.274 lb. gauge 

11—18 



We find an effective differential in pressure between the boiler pressure 
and the pressure losses in the sytem of .500 — .274 = .226 lb. gauge, for main- 
taining circulation in the system during the period of maximum normal 
heating effect. 

This proves that for the above condition, the J^ lb. drop in pressure in 
Pt is the proper basis for selecting the table to be used, and this being de- 
termined, the intermediate sizes of the main and branches 6ire taken from game. 

The sizing of run-outs requires special consideration as described in 
detail in Chapter 12, "Critical Flow of Steam". 

The sizing of returns involves the same procedure with modulation 
systems as outlined before in the discussion of sizing of piping for vacuum 
systems. The size of the return depends on the size of supply for an equal 
duty. By referring to Table 11-5, we find that the size of return correspond- 
ing to a 5 in. supply main is 23^2 i^-) which is the size we select. 

Taking care of the condensation in the steam main at the far point is 
often found necessary in modulation systems in which case the pipe sizes 
must be increased toward the end of the run, beyond the tabular values, to 
take care of the reduction in effective area of the pipe due to the condensa- 
tion being carried along with the steam. 

A further reason for increasing the sizes of the pipes toward the end of 
the run is to compensate for the air carried along with the steam in the pipes, 
which, if not properly reheved, will retard the circulation of steam to a great 
extent. 

Air rehef connections must be provided at the ends of the runs, through 
thermostatically actuated return traps into the nearest dry return, in all 
cases where gravity drips are made into a wet drip line. 

Table 11-6. Flow of Steam at 16 It. per sq. in. Absolute Initial Pressure through 

Mains of 200 to 1000 feet of Run 

Vs-hB. DROP IN PRESSURE 

LENGTH OF RUN IN FEET 



Pipe Size 


200 


300 


400 


500 


750 


1000 


1 


4.7 


3.89 


3.36 


3.0 


2.45 


2.13 


IH 


14.38 


11.73 


10.13 


9.06 


7.4 


6.43 


IH 


24.85 


20.3 


17.57 


15.75 


12.81 


11.13 


2 


58.1 


47.6 


41.16 


36.82 


29.96 


26.04 


2J4 


104.3 


85.7 


74.2 


66.5 


54.11 


46.97 


3 


190.4 


156.1 


135.1 


120.4 


98.35 


85.4 


33^ 


284.2 


233.1 


211.6 


179.9 


14.7 


127.4 


4 


397.6 


325.5 


281.4 


252. 


205.1 


178.5 


5 


707. 


581. 


501.2 


448.7 


365.4 


317.8 


6 


1141. 


938. 


805. 


724.5 


590.8 


513.1 


7 


1666. 


1365. 


1176. 


1057. 


861. 


745.5 


8 


2317. 


1890. 


1638. 


1463. 


1190. 


1036. 


9 


3101. 


2534. 


2198. 


1960. 


1596. 


1386. 


10 


41.51. 


3395. 


2926. 


2632. 


2142. 


1862. 


12 


6524. 


5341. 


4620. 


4130. 


3360. 


2919. 


14 


10080. 


8260. 


7140. 


6398. 


5208. 


4522. 


16 


12495. 


10220. 


8820. 


7910. 


6454. 


5635. 


18 


16940. 


13860. 


11970. 


10710. 


8715. 


7500. 


20 


22260. 


18270. 


15750. 


14140. 


11480. 


10010. 



11—19 



Table 11-7. Flow of Steam at 16 lb. per sq. in. Absolute Initial Pressure through 
Mains of 200 to 1000 feet of Run 

M-LB. DROP IN PRESSURE 

LENGTH OF RUN IN FEET 



Pipe Size 


200 


300 


400 


500 


750 


1000 


1 


7. 


5.48 


4.74 


4.24 


3.47 


3. 


IM 


20.39 


16.53 


14.33 


12.79 


10.46 


9.06 


VA 


35.42 


28.7 


24.92 


22.26 


18.20 


15.75 


2 


82.6 


66.99 


57.75 


51.8 


42.56 


36.68 


2K 


149.1 


121.1 


104.3 


93.45 


76.3 


66.36 


3 


271.6 


219.8 


190.4 


170.1 


139.3 


120.4 


3>^ 


404.6 


328.3 


284.2 


254.1 


207.9 


179.9 


4 


565.6 


459.2 


397.6 - 


354.9 


290.5 


252. 


5 


1008. 


819. 


707. 


633.5 


518. 


448. 


6 


1624.7 


1316. 


1141. 


1022. 


840. 


721. 


7 


2373. 


1918. 


1666. 


1484. 


1218. 


1050. 


8 


3290. 


2660. 


2310. 


2065. 


1687. 


1463. 


9 


4410. 


3570. 


3099. 


2772. 


2268. 


1960. 


10 


5887. 


4788. 


4151. 


3710. 


3038. 


2625. 


12 


9254. 


7490. 


6510. 


6174. 


4760. 


4130. 


14 


14350. 


11620. 


10080. 


8995. 


7360. 


6447. 


16 


17780. 


14420. 


12460. 


11130. 


9100. 


7910. 


18 


24080. 


1946Q. 


169 iO. 


15120. 


12390. 


10710. 


20 


31710. 


25760. 


22260. 


18880. 


16310. 


14070. 



Table 11-8. Flow of Steam at 16 lb. per. sq. in. Absolute Initial Pressure through 
Mains of 200 to 1000 feet of Run 

K-LB. DROP IN PRESSURE 

LENGTH OF RUN IN FEET 



Pipe Size 


200 


300 


400 


500 


750 


1000 


1 


9.38 


7.72 


6.66 


6.04 


4.91 


4.24 


IM 


28.39 


23.46 


19.73 


18.26 


14.79 


12.79 


I'A 


49.28 


40.6 


35.07 


31.78 


25.76 


22.26 


2 


114.1 


94.5 


81.69 


105. 


60.06 


51.8 


2M 


207.2 


170.8 


147.7 


133.1 


108.5 


93.45 


3 


378. 


311.5 


268.8 


243.6 


197.4 


170.1 


Z}4 


562.1 


464.1 


401.1 


362.6 


294. 


254.1 


4 


784. 


649.6 


560.7 


507.5 


410.9 


354.9 


5 


1400. 


1155. 


994. 


903. 


730.8 


633.5 


6 


2261. 


1860. 


1610. 


1456. 


1183. 


1022. 


7 


3297. 


2723. 


2352 


2380. 


1722. 


1484. 


8 


4571. 


3780. 


3262. 


2947. 


2387. 


2065. 


9 


5425. 


5054. 


4368. 


3955. 


3206. 


2772. 


10 


8190. 


6762. 


5852. 


5985. 


4291. 


3710. 


12 


12880. 


10640. 


9170. 


8309. 


6748. 


6174. 


14 


19950. 


16450. 


14210. 


12845. 


10430. 


8995. 


16 


24710. 


20440. 


17640. 


15946. 


12950. 


11130. 


18 


33460. 


27.580. 


23870. 


21560. 


17360. 


15120. 


20 


44100. 


36400. 


31430. 


28420. 


23030. 


19880. 



11—20 



Table 11-9. Flow of Steam at 16 lb. per aq. in. Absolute Initial Pressure through 
Mains of 200 to 1000 feet of Run 



1-LB. DROP IN PRESSURE 

LENGTH OF RUN IN FEET 



Pipe Size 


200 


300 


400 


500 


750 


1000 


1 


13.3 


10.97 


9.52 


8.51 


7. 


6.04 


IH 


40.32 


33.19 


28.73 


25.7 


21.13 


18.26 


iVi 


70. 


57.4 


49.91 


44.59 


36.68 


31.78 


2 


162.4 


134.4 


115.5 


103.6 


85.4 


108.5 


2H 


294. 


242.2 


210. 


187.6 


154. 


133.7 


3 


535.5 


441. 


382.2 


341.6 


282.1 


243.6 


3y2 


798. 


658. 


568.4 


509.6 


420. 


362.6 


4 


1113. 


917. 


795.2 


714. 


586.6 


507.5 


5 


1988. 


1638. 


1442. 


1281. 


1043. 


903. 


6 


3220. 


2646. 


2296. 


2051. 


1686. 


1456. 


7 


4672.5 


3850. 


3339. 


2989. 


2457. 


2380. 


S 


6489. 


5355. 


4634. 


4151. 


3402. 


2947. 


9 


8680. 


7140. 


6202. 


5558. 


4564. 


3955. 


10 


11620. 


9590. 


8295. 


7420. 


6125. 


5285. 


12 


18270. 


15050. 


13090. 


11690. 


9590. 


8309. 


14 


28350. 


23310. 


20160. 


18060. 


14770. 


12845. 


16 


35140. 


28910. 


25060. 


22400. 


18410. 


15946. 


18 


47600. 


39200. 


33950. 


30380. 


25025. 


21560. 


20 


62650. 


51520. 


44100. 


33900. 


32760. 


28420. 



11— 21» 



CHAPTER XII 
Critical Velocities in Radiator Run-outs 

MUCH speculation and uncertainty exists as to the possibility of sup- 
plying steam to radiation through run-outs in which the steam 
condensed in the run-out must draia back against the flow of steam 
to the radiator. 

If the flow velocity of steam is higher than the critical point, the con- 
densation will be swept up the grade to the elbow where the vertical rise to 
the radiator valve occurs and there cause a churning noise and obstruction 
to circulation. 

At first thought it would seem a simple matter to 6irrange a series of 
tests from which the critical velocity at grade could be accurately deter- 
mined. In fact, however, so many variables enter the problem that a series 
of careful tests extending over a long period of time will be necessary to 
obtain results within a satisfactory degree of tolerance. 

The critical velocity evidently varies not only with grade and steam 
density, but also with the amount of condensation. It follows (1) that the 
length of run-out and character of covering are material factors, because the 
longer the pipe the greater the volume of condensation with the same 
difference in temperature between interior and exterior of pipe, and (2) that 
a well-covered pipe will permit much less condensation per lineal foot of run 
than an uncovered one when in the same surrounding space temperature and 
air-flow conditions. 

In practice, consideration must also be given to the liability of back 
flow of condensation from the radiator. This would occur in a one-pipe 
system of radiators if the bottom of the inlet pipe were at lower level than 
that of the outlet, as in cases of concentric tapping with inlet larger than 
outlet. It follows that where eccentric bushing of inlet and outlet is insisted 
upon, and also where run-outs are short or have few turns and are well 
insulated throughout, a higher critical flow may be obtained. 

A series of carefully conducted tests of various sized bare pipes, 18 feet 
long, reasonalDly straight, and set at accurate grades, in a room where 
temptrature averaged 70 deg. indicated critical velocities of steam at initial 
density as shown in Table 12-1. 

Table 12-1. Critical Velocities of Steam in Pipes Surroimded by 70 deg. fahr. 
Room Temperature and Well Insulated 











Velocities in feet per minute 






Grades in 10 feet 


H' 


-V-lVi" 


Pipe 


lU" Pipe 


2" Pipe 




Ysin. 




360 




470 


840 




Va in- 




460 




640 


1070 




J^in- 




640 




910 


1330 




^in. 




830 




1090 


1470 




• 1 in. 




1020 




1210 


1570 




Wiyn. 




1380 




1320 


1730 





12—1 



The highest velocity through run-outs occurs when steam is first turned 
on to cold radiators, at which time the flow is probably fully Vs cu. ft. per 
min. per sq. ft. of average cast-iron radiation. It would, therefore, seem 
advisable, when permissible grade is hmited, to hmit the amoimt of such 
radiation to that shown in Table 12-2. 

Table 12-2. Advisable Limits of Radiation for Various Sizes of Run-outs 

Where Only Small Grade is Permissible 

From tests made on rmi-outs composed of 18 feet of uncovered pipe in a smrounding air tempera- 
ture of 70 deg. fahr. 



Pipe Diam. 


%" 


1" 


IH" 


IVz" 


2" 


Grade in 10 feet 






Radiation in square feet 






Vsm. 


7.1 


11.0 


19.2 


33.3 


98. 


Hia. 


8.8 


13.7 


23.9 


45.3 


125. 


'A in. 


12.2 


19.1 


32.3 


64.5 


155. 


Min. 


15.8 


24.7 


43.1 


77.3 


171. 


1 in. 


19.5 


31.5 


53.0 


86.0 


183. 


VAin. 


25.2 


41.0 


71.0 


94.0 


201. 



Where the run-out has less frictional length, or where pipe is well insu- 
lated, greater ratings may be permissible. Where slow initial circulation and 
noise are not objectionable, these ratings may possibly be doubled. It is 
hoped through further tests and a digest of the results to be able to place 
before the engineering profession formulae from which more accurate results 
may be estimated, although it cannot be hoped to ehminate the uncertainties 
due to inaccurate grading, rough pipe ends cuid other structural defects. 
Accurate results in any case are entirely dependent upon conditions be'ng 
fully equal to those predicated. 



12—2" 



CHAPTER XIII 
Capacities and Ratings of Webster Apparatus 

CAPACITY is a basis obtained from tests under one set of conditions 
from which ratings are deduced for other operating conditions. 
The term CAPACITY is used in "Steam Heating" to denote the 
number of pounds of condensation per hour (Wi) which at uniform flow will 
pass through the specified apparatus when the pressure is maintained at 
1 lb. per sq. in. (Pi) above that of the atmosphere Eind the pressure at the 
outlet is that of the atmosphere (P2). 

Having obtained the capacity of any unit of steam-heating apparatus 
under these standard conditions, RATINGS may be estimated within a 
very small error, for other stated conditions of pressm-e difference, time, or 
the amount of heat content in the steam at given initial pressure. 

For any other pressure difference (P3 — P4) not differing greatly in 
amount from the standard pressure difference (Pi — P2), the quantity of 
discharge (W2) varies from the quantity (Wi) discharged under standard 
conditions in proportion to the square roots of the pressure differences ; that 
is 

W„ = W, 1 ^' ^^ 

^' ^Wpi^^p; 

or so nearly as to be within the normal errors of test. 

The distinction which should be made between capacity and rating, 
especially where rating is expressed in some indeterminate value like "square 
feet of radiation," can best be emphasized by examples. 

Assume a radiator trap, the capacity of which, with a drop from 1 lb. 
pressure above atmospheric in the radiator and trap, to atmospheric pressure 
in the trap outlet, has been found by tests to be 60 lb. of condensation per hr. 

Example 1. At what should this trap be rated in square feet of radia- 
tion on a coil in a room of 60 deg. average temperature, when the steam 
pressure in the coil is 4-lb. gauge and the vacuum, at the trap outlet, is 
10-in. or 5-lb. gauge .^^ 

Answer: The pressure difference through the trap would then be 4 -f- 5, 
or 9 lb. The flow through the trap would be as the square root of 1 is to 
the square root of 9, or three times the capacity of the trap at standard 
1-lb. pressure difference. This figures out 180 Lb. per hr. 

Each pound of steam at 4-lb. gauge pressure gives off in condensing in 
a cofl about 963 B.t.u. of latent heat, a total of 963 X 180 or 173,340 B.t.u. 
per hr. Under the temperature due to 4-lb. gauge pressure the coil would 
probably give off 324 heat units per sq. ft. of surface. Therefore, the 
rating of this trap under the above conditions would be 324 divided into 
173,340, or 535 sq. ft. of direct radiation. 

Example 2. At what would this same trap be rated in square feet of 
radiation on the same kind of a coil similarly placed when supplied with steam 
at ^-Ib. gauge, and exhausting to atmospheric pressure at the outlet.^* 

Ansiver: The pressure difference through trap being as stated, 3^ lb. 
per sq. in., the flow through trap wUl be as the square root of 1 is to the squEire 

13—1 



OPEN 
10- 

1— 
o 
di ■ 

o - 

CD 

o 

|4- 

_C . 

'o 
^ 9 




/ 




^ 






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80 



120 



160 200 240 

Square Feet of Radiation 



320 



360 



400 



root of }/i, or 3^ the rate at 1 lb. difference in pressure, or 30 lb. of steam per 
lir. Each pound of this stetim will give off in condensing about 969 B.t.u. 
of latent heat or 969 X 30 = 29,070 B.t.u. per hour. 

Under the temperature due to J^-lb. gauge pressure, the coil would 
probably give off 300 B.t.u. per sq. ft of surface. Therefore the rating of 
the trap under the conditions of this example would be 29,070 divided by 300 
= 96.9 sq. ft. of direct radiation. 

In Example 1, the rating in sq. ft. of radiation is more than five times 
that in Example 2, the difference being due to the effect of differences in 
pressure on the same trap, which in both cases had the same capacity. 

Webster Modulation Supply Valves. Careful consideration should 
be given to the following facts concerning ratings of this type of apparatus : 

The capacity of a modulation valve should be based on the quantity 
of steam expressed in pounds per hour, or the equivalent B.t.u. of latent 
heat therein at 1-lb. pressure above atmospheric pressure which wUl flow 
tlu"ough the valve when the outlet is at atmospheric pressure. 

This capacity may be referred to as the number of square feet of radiat- 
ing surface which would absorb the total latent heat of the steam flowing 
into the surface in a given time, at the commencement of which the tem- 
perature of the metal of the radiation and the room were at a stated degree 
below the normal room temperature. 

The condensation in radiation is greatest during the warming-up period, 
and a large part of the latent heat of the entering steam will be absorbed in 
supplying the heat requirement of the metal (specific heat). Possibly one- 
haff of the normal B.t.u. of heat flow due to radiation and convection wiU 
also occur during this period. It follows that the longer the heating-up 
period, other things being equal, the greater the portion of the capacity 
which may be expressed in the rating. The consensus of opinion is that 
for a radiator, the basis should be a 20-minute heating-up period from 40- 
degree room temperature. 

As the weight per square foot of the usual types of radiating sm'face 
varies more than 2 to 1, the weights cannot consistently be averaged until 
at least divided into classes, as in Table 13-1. 

Table 13-1. Classes of Heating Surface and Their Radiation Values 

^"age Class Pef^^Ft. Pefsq^Ft. Total B.t^. Hourfy B.t.u. U.ut Cap 

Sperific Radiation *" '^ """^ ^'^ "* S^" ^^ 

Cast-iron direct 148 42 190 570 1.7 

lij-inch Steel Pipe 102 50 152 456 2.13 

Sheet Steel 45 50 95 275 3.16 

The basis of rating should therefore be the average class (unit capacity 
in square feet) divided into the capacity of the wide-open modulation valve, 
thus arriving at the maximum rating of the particular valve for the specified 
class at 1-Ib. differential. The normal average flow to a heated cast-iron 
radiator is about 250 B.t.u. A properly designed modulation valve, when 
.6 open should supply the radiator with 5/12 of the full open flow, which is 
the approximate need for fuU modulation effect. The balance, or 7/12 of the 
opening, is thus available for a quick warming-up period (20 minutes) when 
the valve is fuU open. 

13—2 



Due to the wide difference in area between standard pipe sizes, a valve 
of say 1 in. size must be used on all different sizes of radiators between its own 
maximum rating and that of the next smaller, or ^-inch valve. The 1-in. 
valve wide-open will therefore produce a much more rapid heating-up effect 
when connected to a radiator but little too large for a /^-in. valve, and the 
full modulation effect will be reached much before the valve is 0.6 open, 
at which the maximum radiator would be under full modulation effect. 
This problem is best solved by putting a restrictive valve piece in those 
valve bodies which are used on the lower half of the range. This limits the 
flow at 0.6 open to about half way between the maximum for that peirticular 
valve and the maximum of the next smaller size. In this way, a valve 
having a total range of 45 to 78 sq. ft. of radiation at 0.6 open can be lim- 
ited to 45 to 60 sq. ft. of radiation, thus gaining the whole 0.6 range for 
controlling the degree of modulating effect, instead of commencing to mod- 
ulate only after about 2/3 closed and having but the remaining 1/3 of the 
total movement for graduating the modulating effect. 



Fig. 13-1 
Ratings of Webster Type W Modvilation Valve. Based upon a differential of one pound at the valve 

The capacities of each Webster Type W Modulation Valve at various 
positions of the pointer, both with and without the restricted valve piece, 
are indicated in Figure 13-1, which will assist in selection of a valve of the 
proper size for any set of conditions. 

Initial steam pressure alone is not a correct basis for valve rating or 
sizing. It is safer by far to Eillow for the maximum possible drop in line 
pressure when figuring the inlet pressure at the valve. Similarly, allowances 
must be made for variation in return line pressure, especially with vacuum 
systems. 

"Pounds above atmosphere" or "gauge pressures" are apt to be mis- 
leading. Inlet and outlet pressures are best figured in "pounds absolute." 

The condensation rate of radiation varies with the type of radiation or 

13—3 



coil, its location, and the difference between outside and room temperatures, 
and allowance must be made accordingly. 

The above facts, which hardly admit of argument, are the basis of the 
design and application of the Webster Modulation Valves. These valves, 
selected and applied according to the ratings given below, will be more 
eiiicient and will give better economy than any other manually controlled 
radiator inlet or supply valves. 

Table 13-2. Ratings of Webster Type-W Modulation Supply Valves 
In pounds of condensation and B.t.u. per hour 





MODULATION SYSTEM 


VACUUM SYSTEM 


Size of 
Valves 


Low (1 oz. dif.) 


High (2 


oz. dif.) 


Low (K lb. dif.) 


High (1 lb. dif.) 




Lb. 


B.t.u. 


Lb. 


B t.u. 


Lb. 


B.t.u. 


Lb. 


B.t.u. 


1 " 


11 
23 
38 
61 


10363 
22160 
36700 
62325 


15 
32 
53 
89 


14380 
30760 
50940 
86500 


21 

46 

76 

129 


20725 

44320 

73400 

124650 


43 

91 

151 

2.57 


41450 

88640 

146800 

249300 



Webster Return Traps: Both the Webster Sylphon Return Trap 
and the Webster No. 7 Return Trap are rated on the basis of the quantity 
of condensation which they will pass under stated conditions. For con- 
venience, these ratings are given in B.t.u. and pounds per hour. 

Due to the fact that these traps when cold are fully open, the warming- 
up period of a radiator is dependent entirely on the rate of flow of steam 
units to the radiator tlirough the supply valve and its connecting piping. 

The thermostatically actuated members of Webster Sylphon and No. 
7 Return Traps are sensitive to very slight changes of the temperature of 
the surrounding medium. The motion of the members is due to difference 
in pressure and temperature on a hermetically sealed charge, partially 
liquid, partially gas and vapor, which responds to changes in temperature 
with material changes in volume and pressure, which provides a powerful 
force to actuate the valve piece. 

Table 13-3. Ratings of Webster Return Traps in Pounds of Condensation and 
B.t.u. per Hour at Various Pressure Differences 





Type of 
Trap 


MODULATION SYSTEM 


VACUUM SYSTEM 


Size of 
Trap 


Low (1 oz. dif.) 


High (2 oz. dif.) 


Low f'i lb. dif.) 


High (1 lb. dif.) 




Lb. 


B.t.u. 


Lb. 


B.t.u. 


Lb. 


B.t.u. 


Lb. 


B.t.u. 


Yi" 


512 and 712 
522 and 722 
.533 and 733 
5 14 and 744 
545 and 745 


10 
16 
17 
94 
188 


9700 

15035 

15348 

90696 

181392 


14 

22 

65 

131 

262 


13580 

21049 

63487 

126974 

253948 


19 

31 

94 

188 

375 


18430 

30070 

90695 

181390 

362780 


38 

62 

187 

375 

750 


36860 

60140 

181390 

362780 

725560 



Note: Webster Water-seal Traps in the few cases where they are used 
are rated same as the Sylphons and No. 7 Traps. 

The low modulation rating in this table is based upon a differential of 
1 ounce through the trap, and covers a modulation system where the boiler 
is to be operated on vapor pressure, as in a residence. The high modula- 
tion rating is based upon a 2-ounce differential through the trap and repre- 
sents a modulation system where higher pressure may be carried, as where 

13—4 



the difference between water line in the boiler and the water line in the vent 
trap is 30 inches or more. 

The low vacuum rating represents 3^-lb. differential through the trap 
and would approximate a vacuum system with atmospheric pressure at 
the radiator and a vacuum of 2 in. iu the return line. The liigh vacuum 
rating is based upon 1-lb. differential through the trap and would cover a 
vacuum system with atmospheric pressure at the radiator and about 5-in. 
vacuum in the return line. 

Webster Heavy-duty Return Traps: This trap is for use where 
large quantities of condensation are to be handled at any temperature. 
It has a cone-shaped float-operated valve piece seating on a sharp-edged 
orifice, the seat being below the low-water line of the trap. The air entering 
the trap is allowed to pass to the return line, either through a hand-adjusted 
orifice or through a connection controlled by a thermostatically operated 
trap discharging tlirough a cored passage to the return line. 

Table 13-4. Ratings of Webster Heavy-duty Traps hi Pounds per Hour at 

Various Pressure Differences Through the Valve 

No allowance iiitide for pressure drop in the connecting piping between 
radiation and trap or from trap through run-out to return. 



Size 


PRESSURE DIFFERENCE 


of Trap 


u Lb. 


1 Lb. 


2 Lb. 


3 Lb. 


4 Lb. 


5 Lb. 


10 Lb. 


15 Lb. 


0016 
016 
116 
216 
316 


700 

1250 

2100 

5600 

10500 


1000 
1800 
3000 
8000 
15000 


noo 

2500 

1200 

11200 

21000 


1700 

3050 

5100 

13600 

25500 


2000 

3600 

6000 

16000 

30000 


2200 

4000 

6700 

17900 

33500 


31.50 

5700 

9500 

25300 

47400 


3900 

7000 

11700 

31100 

58400 



Webster Series 20 Modulation Vent Traps: Ratings of Series 20 
Modulation Vent Traps are based on 6000 cu. ft. per hr. velocity of air flow 
through a vent orifice of 1 sq. in. from 1 lb. above to atmospheric pressure. 

It is assumed that 50 sq. ft. of cast-iron radiation with connecting supply 
lines contain 1 cu. ft. of space. The air which must be discharged from this 
space before steam may enter contains about 13.2 cu. ft. per lb. 

The velocity, (V) = C ^ 2 gh, in which C = 0.7 





Table 13-5. 


Ratings of Series 20 M 


odulation Vent Tr 


aps 


Size 


Cubic Feet of 
Air per Hr. 
at 1-Lb. Dif. 


Square Feet of 
Dir. Rad. per Hr. 
at 3i-Oz. Pressure 


Square Feet of 

Dir. Rad. in 40 Min. 

at 1-Oz. Pressure 


Square Feet of 
Dir. Rad. per Hr. 
at 1-Oz. Pressure 


120 
220 
320 


1176. 
2652. 
4710. 


7350 
16575 
29137 


9800 
22100 
39250 


14700 
33150 
58875 



The vent outlets from all three sizes of vent traps are of the same size, 
viz.: \}4: ill- 

The vent opening of No. 120 Trap should be bushed to ^ in. and fitted 
with a M-in- special vent valve. 

The vent opening of No. 220 Trap should be bushed to 1 in. and fitted 
with a 1-in. special vent valve. 

The vent opening of No. 320 Trap should remain full size and be fitted 
with lj:4-in. vent valve. 

13—5* 



CHAPTER XIY 

Vacuum Pumps and Auxiliary Equipment for Webster Systems 

VACUUM PUMPS are used in Webster Heating Systems: 
1. To remove air and other products of condensation from the return 
main where these products cannot be expelled to atmosphere by gravity 
or internal steemi pressure alone. 

2. To induce circulation by reducing the pressure in the return main, 
thereby increasing the pressure differential. 

3. To assist in the complete disposal of the products of condensation. 
Experience indicates two successful types of pump for this service, 

namely, reciprocating steam-driven and rotating electric-driven. The 
steam-driven pump has efficiency and economy in its favor where steam 
at 30-lb. or greater absolute pressure is continuously available and the 
pump exhaust and its contained heat may be fuUy utilized in the system. 
The electric-driven pirnip is generally most efficient where exhaust steam 
from the engines and other sources is continuously available in greater 
quantity than is necessary to supply the heating system — in other words, 
where the exhaust from the vacuum pump to waste would be a loss. The 
electric-driven pump is also preferable when the available Mve steam supply 
is at too low a pressure to operate a steam-driven pump. 

Many rotating pumps in which both air and water were handled in 
one chamber have deteriorated very rapidly in service largely because of 
the grit always present in the condensation. Rotating pumps with one pump 
chamber handling air and vapor and another containing a centrifugal 
impeller for handling the water have proved practical. 

Many variables enter the problem of ascertaining the proper size of 
pump for a given heating system. In the final analysis, good judgment 
based on wide experience in applying a table of probaljle pump displace- 
ment is of far greater value than any theoretical formula. 

Even for a close approximation it is necessary to know enough about 
the heating plan in addition to "the square feet of equivalent radiation" to 
be able to estimate the probable maximum volumes in unit of time of both 
water and elastic fluids of condensation ; also the necessary degree of vacuum 
at the pump and the discharge head against which condensation must be 
delivered. 

The volume of water condensation varies in different installations fully 
40 per cent per square foot of equivalent direct radiation. The volume of 
elastic fluids — air, water, vapor, steam and gases from impurities — also 
varies with the initial and terminal pressures, with the efficiency of the 
radiator traps, with the degree of prevention of inward leakage of air, with 
the probable cooling effect in the return, and with the character of the im- 
purities in the boiler-feed. 

Lifts (see Figure 14-1) in the retiu-n call for lower terminal pressure 
with consequent greater expansion in volimie of the elastic fluids, thus calling 
for greater pump displacement, and, therefore, should be avoided wherever 
possible. 

Discharge head on reciprocating pumps handling water and air has the 

14—1 



effect of increasing clearance and slip and thereby 
decreasing the effective displacement. 

A discharge head of more than one added 
atmosphere on reciprocating pumps is best 
handled by separating the water and gases and 
removing " them independently through 
two separate pumps. 

For shp in reciprocating wet-vacuum 
pumps it is seldom safe to allow less than 
% of the displacement, although a newly 
packed pump may show much less. 



^ 



3 ez 



^ 



Fig. 14-1. Method of Making Step-ups 
Using Webster 1920 Design Lift Fitting 



c* 



3 c 



^ 



Systems in which the pressure 
throughout the supply lines and 
radiation as well as in the returns 
is normally less than that of the 
atmosphere are subject to invisible inleakage of air around the valves and 
fittings. Such systems require increased displacement also, because of the 
greater volume of elastic fluids due to low terminal pressure necessary for 
circulation. 

Cooling and consequent reduction in volume of the elastic fluids in 
return presents an element of considerable magnitude and uncertainty. 

Well-insulated return pipes, also large volmnes of condensation entering 
the main return close to the vacuum pump, require greater displacement 
than would the same radiation with returns in which a considerable portion 
of the vapors had the opportunity to condense between the radiation and 
the pump. 

Clearance reduces effective displacement in all pumps. The clearance 
for a given cylinder diameter in reciprocating pumps of some makes is ap- 
proximately the same in short-stroke as in long-stroke pumps. Commercial 
sizes of reciprocating vacuum pumps vary in ratio of bore to stroke between 
1 to ^ and 1 to 2 ; it follows that a pump of the latter proportion has greater 
efficiency per displacement than the short-stroke pump because of smaller 
percentage of clearance. 

Experience with reciprocating steam-driven vacuum pumps indicates 
that for most favorable conditions the use of water cylinders of less dis- 
placement than eight times the normal volume of water of condensation is 
seldom safe. With radiation divided into small units, a ratio of at least 
10 to 1 will be required. 

Ratings for the rotating combination units should be based substan- 
tially on a 10 to 1 ratio of the combined displacement of water and air cylin- 
ders, the ratio of these cylinders to each other being about 2 of water dis- 
placement to 8 of air. In these pumps the displacement of water must be 

14^2 



high on account of the constant speed, while a low proportion of air dis- 
placement may be taken because of the high efficiency of the air chamber 
as compared with reciprocating pump cylinders which have greater clearance. 
The speed and displacement in rotating pumps are normally constant, 
unless expensive variable speed motors are used, whereas in reciprocating 
steam-driven pumps the piston speed may be varied through a wide range. 
The temptation with the latter is to gain displacement by excessive piston 
speed. 

The time element of stopping and starting the piston and valves twice 
to a cycle should, therefore, be considered, and the piston speed should bear 
some relation to length of stroke. Commercial sizes of reciprocating vacuum 
pumps usually have stroke equal to bore, and have, therefore, been selected 
in Table 14-1 for presenting displacement as a logical basis for estimating, 
within a reasonable tolerance, the proper size of pump to handle the con- 
densation from the wide range of conditions found in vacuum heating 
systems. 

Separate columns of this table give minimum connections of the pump 
and accessories and factors for conditions other than those assumed as 
normal. 

Column 2 gives the basic pounds of condensation and B.t.u. per hour for 
pumps having stroke equal to bore in inches shown on same line in Column 1. 
The basis ratings for each diameter of pump are calculated as shown in 
following example. 

Column 1. Diameter of pump (d) 4" 

Square root of diameter d 2 

Piston travel per hr. 

1200 Vd =2400 

Area in sq. ft. of d 0.0873 

Gross displacement = 1200 x Vd x 0.0873 = 
209.5 cu. ft. per hr. 
Pounds of condensation per hour = 
iV gross displacement in cu. ft. = 20.95 
60 pounds = 1 cu. ft. less }4 for slip = 50 pounds 
Column 2. Basic pounds of condensation = 20.95 x 50 = 1047.5 

average B.t.u. per pound of condensation 970 

Column 2. Basic B.t.u. = 1047.5 x 970 = 1,016,075 

Column 4. In this column £ire factors for converting basic ratings of Column 
2 into ratings for pumps with stroke greater or less than bore, 
the proper multiplier for Column 2 in Column 4 having been 
found in Column 3 under the quotient of stroke divided by bore. 
Example: Assume 4 in. diameter and 6 in. stroke. Find the basic rating. 
Divide 4 into 6, quotient = 1.5. 

Inspection of Column 3 shows 1.5 on a line with 1.19 in Column 4. 
Multiplying basic rating, 1047.5, by Column 4 = 1.19. 
Basic rating of 4 in. x 6 in. pump = 1246 lb. 
Column 5. Approximate size of return graded 1 ft. in 300 to pump, which 
when half filled would deliver net pounds of condensation 

14^3 



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14—4 



(Column 2) by gravity (Q = ac V r s, in which q = quantity dis- 
charged per second, a = cross-sectional area of pipe, c is a con- 
stant, r = hydraulic radius and s = slope of pipe) . 

Column 6. Approximate size of pump delivery pipe from pump to tank, 
based on pipe half filled and slope of 1 ft. in 20. 

Colunm 7. Air separating surface required in cross-section of tank based 
on 1 sq. ft. to 2100 lb. of condensation. 

Column 8 Diameter and length of tank for air separation only, as in 
Eind 9. Hydro-pneumatic or plain tanks. 

Column 10 Tanks in which condensation automatically operates valves, 
and 11. either for admission of cold make-up water or the speed of boiler- 
feed pump connected to tank. These tanks are to be capable 
of storing the normal water of condensation pumped to them 
in five minutes. 

Column 12. Normal size of steam pipe and vacuum governor to pump used 
with boilers of 75 to 125 lb. steam pressure. 

Column 13 Factors for conditions of heating system other than those 
and 14. assumed as normal. 

The normal basis being: 

(a) That such system be continuously supplied with steam at pressure 
above atmosphere and 2 to 3 in. vacuum in return at farthest radiator. 

(b) That average cast-iron radiation units of 20 to 25 square feet direct are 
used. If units average larger than 25 square feet direct and other con- 
ditions are normal, there will be less air to be handled and the displace- 
ment may be less. 

(c) That all units of radiation have standard radiator valves of screw-down 
type. If there is no inleakage around inlet valves, less displacement is 
required. 

(d) That draining of horizontal mains is by gravity drip to hot-weU or 
receiver. If no large volumes of condensation at or near steam tem- 
perature enter return near the pmnp, a smaller volume of vapor is to 
be handled. 

(e) That there are no lift points in return. Lifts require an increased degree 
of vacuum and a greater volume of displacement. 

(f) That returns as well as supphes are insulated. Returns not insulated or 
having some form of coohng coil decrease the normal volume of elastic 
fluids and require less displacement. 

(g) That total run is less than 500 feet from the soiu"ce of steam supply to 
the farthest radiator. The initial degree of vacuum to obtain a terminal 
of 2 or 3 inches at farthest radiator normally increases with length of 
run and calls for greater displacement. 

(h) That aU units of radiation have on their drip connections Webster 
Thermostatic Traps of Sylphon or No. 7 Type. If the traps on the drip 
ends of radiation leak steam at any nornial variations in differential 
pressure tlirough the trap, the volume of elastic fluids to be displaced 
increases with the steam leak and the required degree of vacuum. 
To use this table where the B.t.u. basis of each class of radiation is 

shown in the calculation for heat losses, and the condition of the system is 

14—5 



other than outlined under Normal Systems, multiply the B.t.u. in each 
class by the factor in Column 13 or divide by Column 14 for that class. 
Find sum of all classes when so factored and look in Column 2 for the 
nearest basis rating in B.t.u. to the above factored sum. The corresponding 
diameter in Column 1 will be that of the pump required. 

The sum of factored quantities divided into the basic rating of given 
diameter will give index in Column 3 and factor in Column 4 times given 
diameter will give proper stroke. 

If the result does not fit stock sizes obta'nable, select a stock pump of 
diameter and stroke which when factored by Column 4 will give a basic 
rating at least equal to the factored sum of heat losses. 

In using the table to ascertain a pump corresponding to the radiation 
in square feet, convert the square feet of each class of rad'ation into pounds 
per hour or B.t.u.; multiply the pounds or B.t.u. per hour for each class by 
the factor in Column 13 for that class. Find sum of all classes when so fac- 
tored and look in Column 2 for the nearest basic rating in pounds to the 
above factored sum. The corresponding diameter in Column 1 will be that 
of the pump required. 

The method of finding the required stroke of reconciling to stock sizes 
is to divide required pounds or B.t.u. into basis lb. or B.t.u. and apply 
quotient to Column 3 to find proportion of stroke to bore in Column 4. 

Problem: Find the proper size of water end to handle the condensation 
from Buildings A and B and C wherein all returns are exposed. 

Bldg. A. Blast coils condensing 5000 lb. per hr. 

Closed heater condensing 1000 

6000x970 = 5,820,000 

Bldg. B. 100 pipe coils 130 sq. ft. each approximately 375 

B.t.u. per sq. ft. = 4,850,000 

Bldg. C. 200 direct-indirect radiation, 50 sq. ft., each 

approximately 290 B.t.u. = 2,910,000 

Factoring these B.t.u. results by Columns 13 or 14 we have: 

A = 5,820,000 x .66 = Blower stack and water heater 3,880,000 

B = 4,850,000 x .75 = Coils over 120 sq. ft. 3,637,500 

C = 2,910,000 X .89 = Radiators, about 50 sq. ft. 2,589,900 

10,107,400 

C3iumn2. Nearest diameter under 10 in. 10,029,800 

We nute that the basic rating of a 10-in. bore comes nearest to the sum 
af factored quantities, and we, therefore, select a pump with a 10-in. bore. 

Factored B.t.u. = , nn9Q«nn ^ ^'^^ ^^^ ^'^ (Column 3) 

Basic B.t.u. 

Factor in Column 4 corresponding = 100% = 1 

Bore X Factor (Column 3) = Stroke = 10 x 1 = 10-in. stroke 

We, therefore, use a 10 in. x 10 in. water end, wliich is a stock size. 

T 1 • ■ r' ^ Minimum return 4 to il-4 in. for long run = 4^9 in. 

Lookmg m Column -xu- ■ i- i oi V" • * 

r 1 n 1 -: Mmimum dischEu-ge Zyo m. to an open 

5 and Column 6 . i & / ^ *^ oi / • 

tank = 23^ m. 

Columns 8 and 9. Size of open tank min. 18 in. x48 in., stock size. 

Column 12. Vacuum governor if high pressure steam available, 1 in. size. 

Note: See example of three buildings in Chapter 11. Main, 14-in; Return, 4}^ in. 
14—6 



Proportioning of Steam Ends of Reciprocating Vacuum Pump: 
It is seldom safe to use a factor of less than 100 per cent in proportioning 
area of steam cylinder to area of water and air cylinder. Carelessness in 
setting up the packing in water and air pistons is prevalent and to be expected. 

Necessity for pump to keep going when steam pressure is lower than 
that predicated is another reason for use of above factor. 

For ascertaining the minimum area of the steam piston the following 
rule may be applied: Multiply the area of the water cylinder by the sum of 
the maximum vacuum and discharge head expressed in pounds per square 
inch, and divide by one-half the available gauge pressure of steam at the pump. 

It must be remembered that the available pressure at the pump is 
always lower than that at the boiler. Therefore, for a safe approximation 
of steam piston area one-third of the boiler pressure times the area of steam 
cylinder in square inches should equal the pressure in water end (vacuum 
plus discharge pressure) times the water piston area in square inches, as 
expressed in following equation : 

.3^ A"x (V plus Dp) x3 

in which " 

A^ = Area of steam piston in square inches. 

A" = Area of water piston in square inches. 

V = Suction pressure expressed in pounds = Vacuum in inches divided 
by 2. 

D = Discharge pressure in pounds per square inch. 

B„ = Boiler pressure in pounds per square inch. 

Note : All pressures by gauge. 

Power-driven Reciprocating Vacuum Pumps: Lack of available 
steam pressure to operate the piston in reciprocating vacuum pumps requires 
that some other source of power must occasionally be utilized. Where this 
is the case, a reciprocating pump is in many cases unsuitable because of the 
difficulty in handling the varying load during each stroke and because no 
satisfactory means for controlling the displacement to maintain the desired 
degree of vacuum has yet been devised for this type of pump. 

To move the reciprocating piston in the water cyhnder by means of a 
connecting rod and crank, the latter necessarily rotating at low speed, 
enta.ls gearing or an extremely large pulley and countershafting. Inasmuch 
as the torque varies from almost nothing at the ends of the stroke to a high 
maximum at about three-fourths stroke, back-lash, noise and wear of gears 
or slapping and slip of belts are to be expected unless a heavy fly-wheel is 
used, and in any instance the power consumption is excessive. 

Variable-speed motors are sometimes utilized for driving, but are 
expensive, emd at best give only two or three steps of displacement, which 
must be selected either manually or by comphcated and dehcate electrical 
controllers. 

There is nothing to commend in intermittent control. Constant speed 
and displacement with a vacuum breaker to admit air when the load is 
below normal is probably nearest to a satisfactory arrangement where 
power-driven reciprocating vacuum pumps are used. 

14—7 : 



Disposal of Vacuum Pump Discharge: Conditicns vary to such an 
extent that good judgment is the only safe guide in determining the best 
method for the disposal of the vacuum pump discharge. In no case should 
the head against the discharge of reciprocating pumps exceed 15 pounds 
unless the pump stroke materially exceeds the bore and thus reduces the 
bad effect of clearance. Usually one of the following seven methods will 
best apply. 

1. Discharge to Waste: Disposal by discharge to waste involves loss of 
all the valuable heat and water, but in rare cases this is permissible. 

2. Discharge through Air-separating Tanks: Where first thought seems 
to indicate disposal to waste, it will in many cases be found possible to 
deliver the water and air into a separating tank, or stand pipe sufficiently 
elevated for the water, after separation, to flow by gravity to some point of 
veduable use, such as boiler, feed-water heater, etc. 

Where due to structural conditions, a suitable elevated location cannot 
be found, the effect of head may be obtained by use of a Hydro-pneumatic 
Tank as described under heading No. 4. 

3. Discharge to Open Vent Tanks: Open vent tanks, otherwise called 
plain separating tanks, normally serve the purpose of releasing the entrained 
air from the discharge of the vacuum pimap. (See Figure 14-2.) 



Vent to Atmosphere 




WEBSTER PUIN To Feed-water 
RECEIVING TANK Heater through 
I Loop Seal or as 
-Directed 



Discharge from Vacuum Pump^ 



Floor Line^ 




Lubricator 
Globe Valve 



^Vacuum Pump 



WEBSTER LIFT FITTING 

Fig. 14-2. Method of Connecting Vacuum Pump to a Plain Receiving Tank 



14^-8 



This air removal requires the generous water surface area of either a 
tank of large horizontal cross-section, rather than one of large vertical 
sectional area, or a tank with a large vertical head and enough sectional 
area to permit of low-velocity downward water flow while entrained air is 
floating to the surface against the water current, as in a stand pipe. For 
removal of air, one square foot of horizontal cross-section has usually been 
found sufficient for each 2100 lb. of water per hour. A stand pipe, with 
diameter equal to that of the pump cylinder, is usually sufficient, although 
a more logical rule is to make the cross-sectional area of the stand pipe 
bear some direct relation to the amount of condensation from which the air 
is to be separated, and to the height of column of water through which the 
air bubbles must rise against the flow of hquid. 

The fact that the discharge of reciprocating wet-vacuum pumps is a 
mixture of water and air favors the use of a freely vented separating tank 
wherever a suitable location may be obtained. This is at such height that 
the pressure produced by the water column will be sufficient to overcome 
that in the low-pressure boiler, feed-water heater (see Figure 14-3), or 
other point of disposition. 



Fig. 14-3. Typical application of Webster Water-coiltrol Receiving Tank in connection with an opt-n feed- 
water heater The heater should be set on a foundation of sufBcient height (a vertical rise of not less than 
three feet) betvveen the pump outlet of the heater and the suction vedves of the boiler-feed pump 

14^9 



The effective column or head between the pump-discharge valve and 
the inlet of the separating tank will be less than that of solid water by the 
volume of air contained in the mixture. The contents in separating tank 
and discharge pipe therefrom will be water only. It is, therefore, possible 
with pump discharge properly proportioned and provided with lift fittings, 
vertical rise pipe to tank, etc., to obtain a gravity head in the tank discharge 
above the level of the pump valve deck, considerably greater than the pres- 
sure in the pump cylinder necessary to lift the valves and discharge the con- 
densation to the elevated return tank. 

4. Discharge to Hydro-pneumatic Tanks: As the name indicates, hydro- 
pneumatic tanks bring the elastic pressure of the liberated air to act on 
and supplement the head, in the discharge of the water of condensation. 
A float-controlled valve is placed on the air outlet of the separating tank, 
and so arranged that when the water of condensation has not sufficient 
head to flow by gravity to the point of use, the air will be confined in upper 
p8a"t of tank. As the pump continues to deliver water and air to the tank 



Vent to Atmosphere 



A'utomatic Air Vent Valve 



Automatic Water Relief, 
Valve and Overflow 



Td Br^ unobstructei 
Funnel 



Return ta Boiler 




No. 512 



Motor 



Ctieck Valve/ Valve -B _ 
By- Pass to Sewer^^ Floor Lhie^ 



WEBSTER LIFT FITTINCS 



Fig. 14-4. Method of Connecting Geared Type Vacuum Pump and 
Webster Single-control Hydropneumatic Tank 



14—10 



Vent to Atmosphere . 



Automatic Ki Vent Valve 



Automatic Water Relief 
Valve and Overflow 



To Drain unobsuucted- 




Eqiraftzlng Line connect to 
Boiler at Point tiaving no 
Steam Flow. 



WEBSTER 
BOILER FEEDER 



HIgti Water Line 

of Boiler\ 12'' / 



"Valved connection from 
Low Pressure Steam 
Main to Steam Gauoe 



-Pump Discharge 




WEBSTER 
-HYOROPNEUMATIC TAKK 



WEBSTER LIFT' Drtin to Sewer VWEBSTEH SUCTION STRAINER 
FiniNJS 

Fig. 14-5. Typical Connections to Vacuum Pump, Double-control Hydro-pneumatic Tank and Boiler Feeder 

(see Figure 14-4) the pressure inside the tank increases until sufficient to 
discharge the water, thus lowering the water line and eventually permitting 
escape of the surplus air through the float-controlled air valve. 

The discharge of condensation to low-pressure boilers, in which the pres- 
sure may at times be less than that of the atmosphere, requires another 
float in the hydro-pneumatic tank (see Figure 14-5) to control the valve 
on the tank water discharge and keep this pipe closed at such times as there 
might be danger of air flowing from the tank to the boiler. 

The hydro-pneumatic type of tank is used only where an open tank 
cannot be located at a height sufficient to provide gravity head to discharge 
the tank contents against the maximum pressure in the heater or boiler, or 
where there are large variations between the maximum and minimum pres- 
sures to be overcome. Where the hydro-pneumatic tank is used merely as 
a substitute for an open separating tank, little advantage may be taken of 
the high density of the pump discharge. 

The confined air pressure in the hydro-pneumatic tank plus the gravity 
head in the tank discharge pipe must be sufficient to cause flow to the place 
of disposition. This confined air pressure plus the column of mixed air and 
water in pump discharge to the tank is the total head against which the 
pump must act. 

14—11 



Where pressme on the heater, boiler, etc., varies materially from time 
to time, but in general is near the minimum, a substantial saving in energy 
may be obtained by using a hydro-pneumatic tank instead of a plain tank 
set at higher elevation to overcome the peak pressure in the boiler or heater. 
The use of a plain tank under these conditions keeps the pump operating 
constantly against the maximum head, where a hydro-pneumatic tank set 
lower operates as a plain tank whenever the gravity head in the tank is 
sufficient to cause How at the low elevation, and employs the combination 
of air pressure and gravity head (with air vent closed) only at times of peak 
load. Only for this short time is the air pressure load added to the pump 
discharge. 

5. Discharge to Loop Seal on Tank Outlet to Heater or Boiler: The dis- 
posal of water of condensation from a return tank to a feed heater (see 
Figure 14-6) , boiler, or other receptacle, in which there may be greater pres- 
sure than that of the atmosphere, requires guarding against back flow of 
steam, air or whatever other elastic fluid may be present at the outlet. 



'Vater Control Valve^ 
jid Water Connection. 



Overflow to Waste 



Discharge Irom 
Vacuum Pump — 



Multiply maximum bacit pressure 
carried in healer by 3 to determine 
least dimension In feet 




I'ig. 14-6. Vacuum Pump Connections to Open Heater Usinf; Single Control ilydro-pneumatic Tank 
14—12 



^ 



^Djecharce tr om Vai ^ ui-m P-j mfi 



WESSTEH COMBINATION GAUUES 
Globe Valve-^^^aj 



^ 




Miobc vsiv«j 



Steam to Vacuum Pump 



Builei Keed Pump' 
and iieceiver 



Drain to Sewer 
Check Valve 



WEBSTER LIFT FITTING 
Fig. 14-7. Method of ConnecUn{j: Vacauin Pump and A.utomatic Boiler-ft?ed Pump and Receiver 



Vent to Atmosphere 
Run 10 Air above Root- 



4t 



To Drain 
unobstructed 



Blind Nipple 

a=4 




■Pump Control Valve 



-G^uge Glass 



Funnel - — "ll 



Steam to Boiler 
" Feed Pump 



To Boiler Peed Pamp- 



Qonuection ft-iom Low 
Pressure Steam Main 
-to Steam Gauge 



-Qischange'fiTtOJii -Pump to Tank 



^-"■--Sieam to 
Vacuum Pump 




-Globe V51v£ 



'Vacuum Pump 



WEBSTER LIFT FITTING 



WEBSTER SUCTION STRMNER 



Fig. 14-». 



Method of Connecting Vacuum Pump, Boiler-feed Pump and 
Webster Steam Control Receiving Tank 



14—13 



A loop seal has been found most suitable for this purpose, provided the 
seal is made long and contains ample volume in the vertical leg on the 
pressure side. A variable pressure when increasing tends to force the level 
of water down in the leg on the pressure side and up in the leg toward the 
tank. If there is not sufficient water in the loop, the water will become 
displaced, and the seal broken before enough of a water column has been 
built up in the leg from the tank. The column will then blow into the return 
tank and the steam or other elastic fluid will continue to blow while its 
pressure is above that at the tank outlet. 

The fact that water in the tank is ready to seal the loop below will 
not avail as long as there is a difference in pressure between the tank and 
boiler sufficient to blow a compeiratively short slug of water back into tank. 
The only way to restore the seal is first to equalize the pressure on both 
legs. A good practice is to proportion the leg on the pressure side to hold 
twice the contents of the pipe from the tank to the bottom of the seal. 

6. Discharge to Receiver and Boiler-feed or Tank Pump: Where the head 
on the d?livery side of steam-driven vacuum pumps exceeds 15 pounds, it 
is good practice to dehver the condensation to a vented receiver (see Figure 



Connection from Low Pressure 
^Sleam Main to Stegnt Gauge 
WESSTER 
COMBINAnO^I GAUGES 



Steam to Vacuum Pump"" 




Fig. 14-9. Method of Making Connections to Steam-operated Vacuum Pump 



14^14 



11-7) located close to the level of the vacuum pump outlet. This receiver 
should be connected to a separate steam or power-driven water pump which 
is capable of delivering against the maximum head. (See Figure 14-8.) If this 
pump is steam-driven, its displa'cemmt should be controlled by a throttle 
valve, actuated by the water line in the receiving tank; if power-driven, the 
effective displacement may best be controlled by a by-pass valve between 
pump suction and delivery, and actuated by a float on the water line in the 
receiver. 

7. Discharge to Dry-vacuum Pump Receiver and Water Pump: This 
combination proves very effective under conditions of high delivery head 
where the main return can be arranged to flow by gravity to a closed receiver, 
which in turn is sufficiently elevated alcove the location of water pump to 
provide a head of 2 to 3 pounds on the pump inlet valves: 

The dry-vacuum pump being free from dirt and abrasive material, may 
have close clearance and fairly high efficiency. It may be located above 
and take its suction from the top of the receiver, and frequently some form 
of condenser may be arranged in the suction line to 
absorb and utilize otherwise wasted heat from the air 
and water vapor and at same time materially reduce 
the volume of vapor to be handled. 

The receiver, if properly designed, forms a re- 
ceptacle for the grit and unpurities which would 
otherwise injure the water pump; and it also affords 
space for a float governor for controlling the water 
pump by the varying volume of return water. 

Excessive vacuum in a receiver will cause trou- 
ble in the water pump. For this reason, a vacuum 
governor should always be used to control the dry- 
vacuum pump and to hold the 
vacuum well within the pre-deter- 
mined limits. 

Suction Strainers : The worst 
of the grit and dirt from conden- 
sation should be retarded and re- 
moved before entering the pump 
where it would score the water cyl- 
inder. Strainers (see Figure 14-9) 
with readily removed baskets for use 
on the main vacuum return line were 
first designed and recommended by 
Warren Webster & Company 23 
years ago. The original Webster 
design with little modification has 
been almost universally adopted. 

Vacuum Governors : In steam- 
driven pumps, control of displace- 
ment by the degree of vacuum main- 
tained in the return line may be 
effectually accomplished by throtthng the steam supply. (See Figure 14-10.) 
Simple forms of diaphragm-actuated throttle valves will control the degree 
of vacuum in the main return within sufficiently narrow limits for all 
practical purposes. 




WEBSTER 
VACUUM GOVERNOR 




Fig. 14-10. Connections for a Webster Vacuum-pump 
Governor 



14—15^ 



CHAPTER XV 

Applications of Webster Systems to Slashers and to Cloth and 
Paper Drying Apparatus 

SLASHERS are used in the textile industry for sizing and drying warps 
or yarns before they are placed in looms to be woven into cloth. In 
these machines, steam is supplied usually to two cyhnders, of five and 
seven feet diameter, over which the yarn passes to be dried after sizing. 

Ordinarily the steam supply and the drainage connections are on op- 
posite heads of the cylinders, the connections passing through the cored 
shafts upon which the cylinders revolve. Steeun is carried through the 
mains to the slasher at high pressure and before it enters the cylinders is 
reduced to between 5 and 12 pounds per square inch by a pressure-reducing 
valve. The steam pressure in the cylinders must of course always be above 
that of the atmosphere as the rapid drying of the materials demands that 
the surface temperature of the cylinders shall be above the atmospheric 
boiling point. 

Owing to the light weight of the metal used in construction of slashers, 
vacuum breakers, usually three in number, are provided in the head of the 
discharge side of each cylinder. These open when a partial vacuum occurs 
in the cylinder and prevent collapse of same. 

The condensation is raised to its point of removal from the slasher by 
means of troughs or buckets, usually three in number, attached to the in- 
side cylindrical surface. A pipe attached to each bucket carries the conden- 
sation to the hollow cylinder shaft and thence through the bearing to the 
outside. From there the condensation goes through the Webster Traps, 
etc., to the point of disposal. 

The Webster System for draining slashers provides the most efficient 
drying effect with least attention to the drainage equipment. It has suc- 
ceeded in overcoming entirely the frequent delays and slowing down of the 
manufacturing processes previously experienced with other devices. 

As wiU be seen in Figure 15-1, each cylinder is equipped with a Webster 
Return Trap, a Webster Dirt Strainer and a bull's-eye sight glass. 

The Webster Return Trap permits the free passage of air and water 
and closes against the discharge of steam. The Webster Dirt Strainer 
protects the trap from dirt and the sight glass enables the operator to see 
whether or not the drainage system is functioning. 

A by-pass is provided around the drainage appeiratus. When starting 
up, the by-pass may be opened for a few minutes to permit the quick dis- 
charge of air. After starting the slasher is drained automatically through 
the Webster equipment. 

A pressvu-e sufficiently above that of the atmosphere must be carried 
in the cylinder to dry the goods and this is sufficient to discharge the con- 
densation and air through the Webster Ti-ap, if free vent to atmosphere is 
maintained. There is no advantage in connecting the discharge of the traps 
to a vacuum pump if sufficient vertical distance is available to aUow a proper 
fall for the condensate to flow by gravity to an open receptacle. 

15—1 



The condensation rate with this type of slasher will vary from 400 to 
600 pounds per hour. 

One of the best-known American manufactm-ers of slashers states in 
his catalog: 

"We strongly reconunend the use of Warren Webster & Co.'s appara- 
tus for slasher drainage. 

"Steam traps can be furnished if desired but we recommend the use of 
the Webster System in preference, as higher economy will certainly maintain 
a higher rate of production and its simphcity lessens the hability of stoppage 
to which a system of steam traps is apt to be subject after a few years of use. 




Long Sweep Tee J] I Gate Valve 

To Drain'' WEBSTER SIGHT GUSS 

Fig. 15-1. Typical application of Webster Vacuum System to a slasher. 



15- -2 



" The Webster System as compared with a steam-trap system insm^es 
steady, instead of intermittent, drainage and practically an entire absence 
of condensation in the cylinder with all consequent advantages." 

Cloth and Warp Drying Machines — Except in details, the process 
of draining drying machines of both vertical and horizontal types (shown 
in Fig. 15-2) is the same as for slashers. 

Each cylinder is provided with troughs or buckets which, as the cylinder 
revolves, empty through a pipe to a hollow shaft and through the journal 
to the return duct. 

The housings of the machine and the brackets supporting the cylinders 
are cored to provide ducts for conveying steam to the cylinders and con- 



Air Vent open to Atmosphere 




^Connect to Hot Well, or Drain mdependently 

Fig. 15-2. Application of the Webster System to a vertical drying machine. 

"A" Solid copper gasket inserted between bracket and housing. A copper gasket having hole equal 
in area to that in the bracket must also be placed between the bracket and housing on the inlet <ide to keep 
cy-inder ajgnment true. "B" Gate Valve. "C" Webster Dirt Strainer. "D" Webster Return 
Trap. "E Webster Bull's-eye Sight Glass. 

15—3 



densation away from them. The frame on one side acts as a supply pipe 
while that on the other side acts as a return. Steam at a pressure of 15 
pounds per square inch or less is admitted to the housing and passes through 
the brackets and the journals to the cylinders. To prevent collapse, vacuum 
breakers are installed in the cylinder heads, usually on the discharge end. 

Frequently it is advisable to make two or three separate steam supply 
connections to each housing, as the area of the cored opening in housing is 




Utlion-^ 



^WEBSTER DIRT STRAINER 
WEBSTER HEAVY DUTY TRAP" 

Fig. 15-3. Application of the Webster System to paper machine. 



15—4 



J. 



too small to convey the required amount of steam without too great a pres- 
sure drop. 

The duct in the housing through which the products of condensation 
pass can best be drained by the use of one or more Webster Heavy-duty 
Traps provided with thermostatically controlled air by-pass. 

Paper Machines — Two types of machines of particular interest are 
used in the manufacture of paper — Cylinder Machines and Fourdrinier 
Machines. Both require the evaporation of large quantities of water from 
the paper after the pulp has been pressed and the web has formed. 

After passing through the presses the paper usually contains about 45 
per cent of water. This moisture is reduced to about 5 per cent, depending 
upon the thickness of sheet and the finish desired, by passing the paper 
over a series of drying cylinders, the inside surfaces of which are heated by 
either exhaust or live steam at low pressure or a combination of the two. 

Usually the steam-supply header 
runs parallel with the machine, close 
to the floor, a hole being bored in the 
header and connected toy a pipe to the 
cored journal on the cylinder. 

The return header runs either 
above or below the steam header and 
ha? the same kind of connections as 
the supply. 

The drying cylinders vary in size 
and length. For the purpose of re- 
moving the water, one type of cylinder 
is equipped with buckets and another 
17- ,c A TVT *i J f . • • r J f with what is termed a siphon pipe. 

I^is. 15-4. MetQod of draining cvlinaer of a /-,ii ■ i •tiiiil- 

paper machine using Webster Return Trap and CyLnderS equipped With buckctS dlS- 

Webster Dirt Strainer These connections are charge the Condensation Ouly whcU 

suitable tor operation with either vacuum or gravitv . , • i -i . i • i -ii 

discharge. m motion, while those equipped with 





Fig 1.5-.5. Method of draining cylinder of a paper 
machine using Webster Heavy-duty Trap and Web- 
ster Dirt Strainer and a Webster Return Trap for 
air vent discharging into dry returns. 

15—5 




Fig. 15-6. Method of draining cylinder of paper 
machine for gravity discharge where a water line 
is to be maintained, using Webster Heavy-duty 
Trap with balanced steam connection, Webster 
Dirt Strainer and a Webster Return Trap for vent 
discharging into dry returns. 



siphon pipes discharge whenever water accumulates, provided there is suf- 
ficient pressure in the cylinder or vacuum in the return line to give the neces- 
sary differential. 

The condensation per square foot of exposed drying surface of the 
cylinders depends upon the speed of operation and the thickness and width 
of the paper on the cylinders. The stock from which the paper is made, 
together with the amount of water extracted by the press rolls, also has a 
direct bearing upon steam consumption. The condensation will average 
about IJ/^ pounds per square foot of total roll surface and naturally is greatest 
at the wet end of the machine. 

The drainage from the cylinders may be removed either by gravity or 
by means of a vacuum pump, whichever is desirable. 

Usually with the Webster System of drainage, a Webster Retinrn Trap 
with its Webster Dirt Strainer and By-pass is provided for each cyhnder as 
shown in Figures 15-3 and 15-4. All traps discharge into a main return 
which leads to the point of disposal — which is a feed water heater or hot weU 
— open to the atmosphere for the removal of air. 

vV^ebster iiavy-duty Traps are sometimes used instead of Webster 
Return Traps (Figure 15-5) especially where the presence of a water line is 
desirable in the return (See Figure 15-6). 



1&-6 



CHAPTER XVI 

Applications of Webster Systems to Vacuum Pans and 
Similar Apparatus 

IN processes of manufacture where boiling of the product at a low 
temperature is necessary or desirable, a special application of the 
Webster System has been devised for removing air and water of con- 
densation. 

One of the important uses for vacuum pans is in the milk-condensing 
industry and in the following pages this particular apphcation of the Webster 
System is discussed. However, the principles and the Webster apparatus 
are equally applicable to other processes such, for instance, as the manu- 
facture of sugar, salt, candy or tartaric acid. 

The development and growth of the mUk industry has reached a point 
in the last few years where it is now necessary, due to keen competition, to 
use not only the most modern and efficient machinery in the process of milk 
manufactm-e, but to install modern power equipment and a perfect system 
of steam circulation in order to insure the commercial efficiency of the plant. 

It is essential that each pound of steam (live or exhaust) shall do the 
maximum of useful work and that all water of condensation shall be returned 
to the boiler. 

There are numerous uses for exliaust steam in the modern condensory, 
such as heating of boiler feed water, heating of water for general use and in 
the heating system of the building, but as a rule these require only a small 
portion of the amount of steam available from the exliausts of the engine, 
compressors, pumps, etc. 

In a condensory of say 100,000 lbs. capacity of milk daily, there will be 
available at least 200 h.p. of exhaust steam, not over 20% of which is re- 
quired for any of the above uses. The remaining 160 h.p. of exhaust steam 
is available for use in the vacuum pans. 

The usual practice in the past has been to use live steam in the heating 
coils of the vacuum pan at a pressure of about 15 to 20 lb. gauge, reducing 
to this pressure from the high-pressure mains. Very often excess exhaust 
steam from the engines has been wasted to the atmosphere, being considered 
a by-product of the engine room with little value excepting for its uses in the 
boiler room. Exhaust steam at 5-lb. gauge pressure contains about 88 per 
cent of the heat content of the live steam used to develop power and is just 
as effective in the coils of the vacuum pan as live steam reduced to the same 
pressure. 

To make use of exhaust steam at 5-lb. gauge pressure where live steam 
was used in the vacuum-pan coils, only slight changes are necessary. Oc- 
casionally the sizes of coil connections must be increased to the size of the 
coils themselves and where the steam pressure is decreased, a slight addi- 
tional amount of heating surface in the coils will be required on account of 
the lower temperature of the steam at this pressure. In some plants where 
exhaust steam has been substituted for live steam without changes in the 
heating surfaces, a slight additional time was required to condense the batch 
of milk. In most cases this increase was not more than ten minutes. 

16—1 



The usual control valve connections, that is, the double globe valve and 
a gauge attached to each coil connection, will be the same for use with the 
exhaust steam as with the live steam. 

The return connections for use with the exliaust steam are very simple. 
A single Webster High Differential Heavy-duty Trap (see page Q Chapter 
XVI) with a by-pass is connected to each coil outlet. These traps discharge 
to the return mahi leading to a vacuum piunp in the boiler room. It is 
essential that each coil sliall be drained separately into the vacuum return 
main in order that the pan operator may have absolute control of the steam 
pressure in each individual coil. 

It is necessary when condensing milk to vary the pressure in these coils 
at will. In some instances the pressure in certain coils must be reduced to 
atmosphere, while the pressure in other coils is increased to as high as 5 
lbs. per square inch in order to cause a positive circulation of milk within the 
pan. Without this positive control of circulation it is impossible for the 
pan operator to properly manipulate the process. 

It is also imperative that the water and air of condensation shall be re- 
moved immediately from the coils of the vacuum pan and that this shall be 
accomplished independently of any conditions which may affect the opera- 
tion of the general exliaust steam system in the plant. 

It is advisable to use an independent pump and return line for the vacu- 
um pans and not to depend upon other similar equipment which may be 
used for heating the building. The return line should have a gradual gravity 
pitch to the vacuum pump and should be so arranged with by-passes and 
valves that in case the vacuum pump should become inoperative for any 
reason the return condensation may be discharged by gravity. There must 
necessarily be no pockets of any nature in this return line. 

A maintained vacumn of 6 to 8 inches at the outlet of the trap is usually 
sufficient to insure at all times a positive circulation of steam and the in- 
stant removal of all water and air of condensation. 

Not only are much better results obtained by the certainty of this cir- 
culation, but in many cases where exhaust steam has been substituted for 
live steam a marked improvement in the flavor of the product has been 
noted. 

The great saving in steeun consumption in a condensory when equipped 
with the Webster System will usually pay for the entire installation within 
a few months. However, a careful analysis must be made of the existing 
conditions of an old plant or the requirements of a new condensory before 
any exact arrangement can be determined. There is no other single im- 
provement to a condensory that will approach the saving obtainable through 
the economical use of exhaust steam. 

Figure 16-1 shows an older type of connection for vacuum pans, in 
which liigh-pressure steam only is used. The pressure is reduced from 
125 lbs. per sq. in. boiler pressure to 15 or 20 lbs. per sq. in. for use in the pan. 

The outlet connections are pipes without valves or checks, leading to a 
header which is piped to a tank located beneath the pan. The tank is a 
rsceptacle for water and air by condensation. The air is vented through 
the small vent valve while the water is drained to a high-pressure positive 

16—2 




Fig. 14-1. Milk Condenser. 



16— 2a 



Pressure- rediicino Valve 

T" ^Valve 




I 



I 



^ 




lUHPHmfc:^ 



Positive Return Trap 

o 



WEBSTER 
EECEIVJN.G TANK 




To Boiler Boom 



Fig. 16-1. Drainage System for a vacuum pan using a positive return trap 
and receiving tank 



return trap which discharges the water to an open hot well or to a feed 
water heater. 

The difficulties encountered in this construction will be short-circuiting 
of the steam from one return to the other and the impossibility of maintain- 
ing independent or separate pressure control on each coil in the pan. 

The system of piping, however, is in common use in most of the smaller 
condensories at the present time. 

Figure 16-2 shows another construction where the inlet connections are 

16—3 



similar to those in Figure 16-1, but where the outlet connections are con- 
trolled by means of gate valves and check valves which discharge into a 
common return line. This return line is run direct to a pump and receiver 
which discharges the water back to the boiler. A great many installations 
are somewhat similar to this and it is evident that there is a great deal of 
waste of steam due to the inability of the operator to properly throttle the 
controlling valves on the outlet connections. 

Figure 16-3 shows the approved application of the Webster System. 

The exhaust-steam piping includes a Webster Steam and Oil Separator 
and an auxiliary connection from the high-pressure main with pressure- 
reducing valve. It is essential that the pressure-reducing valve shall be of 



Pressure- reducino Valve 



I 




11° ir 



Fig. 16-2. Drainage System for a vacuum pan using a pump and receiver 



16—4 



I 




Return to Vacuum Pump 
Fig. 16-3. Approved maimer of applying the Webster System to a vacuum pan 

such construction that it will maintain constantly the pressure which is de- 
sired when it is necessary to use live steam for condensing. The back- 
pressure valve must be of such construction that it is impossible at any time 
to exceed 10 lbs. per square inch pressure on the low-pressm"e mains. 

The outlet connections from the vacuum pan are run direct to the 
Webster High Differential Heavy-duty Traps, which are provided with by- 
passes and thermostatically controlled air lines and are connected directly 
to the vacuum return line, which is run through a Webster Suction Strainer 
to the vacuum pump. These outlet connections also must be equipped with 
small try-cocks in order that the operator may test the working condition 
of any coil in the pan at any time. 

16—5* 



CHAPTER XVII 

Application of Webster System to LiiroLer and Other Kiln- 
Drying Problems 

PROPER seasoning and drying of raw lumber is a first essential to well- 
finished products in any wood-working industry. 

This basic condition makes the dry kiln or room a most important 
feature, for as proven by experience in many instances lumber that was found 
defective when worked would have been satisfactory if proper methods had 
been applied for drying. Very CEireful attention should therefore be given 
to the design of the drying room, the character of apparatus used and the 
heating medium employed. 

The method to be employed in drying will depend entirely upon the 
condition of the product when put in the kiln. Green lumber, or lumber 
having a high percentage of moisture, will require a different method of 
procediu-e, and a longer time to dry than lumber which has been air dried. 
Hard woods such as oak or hard maple usually require a longer time than 
soft woods. 

Saw mills should determine the percentage of free moisture by test and 
so mark each pile of lumber when first piled in the yard. Later, when it is 
sold, the lumber should be tested again and the two records given to the 
factory or other purchaser. 

Factories should test and mark the lumber when first received, and if 
it is piled in the yard to be kiln dried later, it should be tested before going 
to the kiln and again before removal, these records being placed on file. 

Oak or any other wood that shows 25 to 30 per cent of moisture when 
going into the kiln wiU take longer to dry than it would if it contained 15 to 
20 per cent. This indicates the importance of testing the lumber before 
putting it into the kiln, as weU as when taken out. 

Kiln-dried lumber piled in storage rooms without any heat will absorb 
7 to 9 per cent of moisture, and when so stored, should be tested for moisture 
before being manufactured. Dry storage rooms should be provided with 
heating coils and should be properly ventilated. 

It is unusual to work through the factory lumber which has more than 
5 or 6 per cent of moisture, or less than 3 per cent. 

Green lumber contains a certain amount of free moisture in excess of 
the fibre saturation point. If the lumber is partially air dried, a considerable 
amount of the free moisture may have been removed. The fibre satura- 
tion point is generally about 25 to 30 per cent. 

A primary test will reveal whether or not the lumber contains more than 
this amount, and subsequent tests at intervals of from two to three days will 
reveal the progress of the drying within the kiln and will inform the operator 
when to change the conditions within the kiln. 

The process required for the drying of lumber in kilns is properly 
divided into four parts, as follows: 

First — The primary treatment, during which all dampers are closed, 
100 per cent humidity is maintained and the stock is warmed through 
without drying. 

17—1 



Second— The initial drying period, during which the conditions of tem- 
perature and liumidity within tlie kiln are advanced sufficiently to reduce 
the moisture content to 25 per cent. 

Third — The intermediate drying period, during which drying condi- 
tions are still more advanced to reduce the moisture content to 10 per cent. 

Fourth — A final drying period, during which extreme conditions are 
used to further reduce the moisture content to the percentage desired. 

Improper drying methods will usually result in one or more of the fol- 
lowing conditions: 

(1) Percentage of moisture not correct for working. (2) Case harden- 
ing. (3) Hollow-horning or hon:!y-combing. (4) Molding. 

The operator should make careful test readings to determine the mois- 
ture content both before and during the drying of the lumber. 

Records from such tests will give data on which to base his treatment 
of the stock. Tests should be made at stated intervals of 48 to 72 hours 
during the drying period. For this purpose test boards from which samples 
may be taken should be inserted in the kiln. A good solid heavy piece as a 
sample, or better still, two or more sections out of as many different boards 
taken out of the pUe one-third the distance from the bottom, will yield an 
average or representative test for moisture content. With two or more 
tests for moisture showing varying results, it is safer to use readings showing 
the highest moisture content rather than the average of the pieces. 

At the same time, tests should be made for case hardening. If the 
lumber become^ case hardened, it practically stops the drying process, or 
at least slows it to a great extent. Frequently this results in hollow-horning 
cupping, internal strains and many other evils which affect the stock through- 
out the manufacturing process. 

Almost all "working" which occurs in furniture, or other wood articles, 
is due to stresses which developed in the wood during the seasoning period. 
These stresses may be determined by two simple tests and ehminated before 
the stock leaves the kiln. 

The manufactiu"ers of the different makes of dry kilns furnish detailed 
instructions for the various tests on which the successful operation of their 
kilns depend. 

The final condition of the lumber required in different factories varies 
with the purpose for which the lumber is used. For instance, in wagon 
work, many manufacturers do not use lumber containing less than 10 to 
12 per cent of moisture; in auto body work, for open bodies, 6 to 8 per cent 
is considered proper; for closed bodies, 5 to 6 per cent. Furniture manufac- 
turers generally dry down to 4 to 6 per cent., while wheel manufacturers 
dry the spokes as nearly bone dry as possible, but do not dry the felloes 
below 8 per cent, the theory being that when the wheel is made the spokes 
may absorb moisture and make a snug fit. 

A modern kiln is usually cDnjtructed with brick side walls and a roof 
of tile or cement covered with roofing felt, tar and gravel. The doors are 
of special design to allow for easy loading and unloading, and to prevent, as 
much as possible, air leakage and loss of heat. Ventilating flues are provided 
in the side walls for supplying air and removing same as desired. 

17—2 



The heating medium usually employed is steam at varying pressures, 
depending upon the kiln temperature desired. The temperature within 
the kiln is controlled by means of a thermostat operating a valve in the pipe 
supplying steam to the coils. 

A system of steam spray pipes is provided under the material to be dried 
for increasing the humidity as desired and to assist in warming the stock. 
The percentage of humidity in the kiln may be automatically controlled by 
means of a humidistat operating a valve controlling the supply of steam to 
the spray pipes. 

Where steam, whether exhaust from engines and auxiliaries, or taken 
direct from the boilers, is used as a heating medium, the success of the 
drying equipment depends upon the manner of carrying this steam to the 
heating units, the proper drainage of the supply mains, the circulation of 
the steam through the heating units and the removal of air and water of 
condensation. 

All manufactures of drying equipment utilizing steam as a heating 
medium recognize the importance of these features. One of the largest 
manufacturers of drying equipment in the United States says in its book of 
instructions : 

"Where troubles have been experienced, investigations have shown that 
they are generally due to one or more of the following conditions: 

"Poor steam service. 

"Pressure not constant. 

"Wet steaYn due to improper condensation drainage. 

" Insufficient steam pressure. 

"Poor drainage from traps. 

" Improper design of supply and drainage piping. 

"Traps allowing steam to blow through into the main drainage line, 
holding back kiln drainage. 

"Traps on heating units not functioning properly. 

"Traps stopped with scale or dirt. 

"Trouble is often caused by faulty design in making steam connections 
to kilns. 

"All steam lines must pitch in the direction of steam flow. Automatic 
drain traps must be provided at all low points on these lines in order that 
there may be absolutely no condensation lying in the lines at these places, 
and that steam may enter the kiln dry and at a high temperature. Failure 
to provide proper methods of drainage will result in reduced volume and 
temperature of steam and correspondingly low temperatures and poor ser- 
vice in dry kilns." 

The important features in connection with the steam supply and drain- 
age system can be enumerated as follows. 

(1) Pressure of steam supply. 

(2) Manner of conveying steam to coils. 

(3) Method of di-aining main steam supply. 

(4) Cha'acter of design of heating units. 

(5) Method of air removal from heating units. 

(6) Method of removal of condensation from heating imits. 

17—3 



(7) System of drainage piping. 

(8) Ultimate disposal of water of condensation. 

Items one, seven and eight wiU be governed materially by the condi- 
tions existing at the plant where kilns are to be used, and as these conditions 
vary with the character of the plant, this discussion wiU be limited to the 
requirements of the kiln only. 

The pressiu-e of steeun supply, so far as the operation of the kiln is con- 
cerned, will depend upon the temperature required within the kiln. If a 
maximum kiln temperature of not more than 160 deg. fahr. is required, satis- 
factory results can be obtained by the use of exliaust steam from engines 
and auxiliaries at a pressm-e not to exceed \}/2 lb. gauge pressure. The same 
results will be obtained, of course, by using steam direct from the boiler 
reduced to a corresponding pressure by means of reducing valves. 

Where temperatures greater than 160 deg. falu". are required it will be 
necesseu-y to increase the pressure of the steam accordingly. In good 
practice the temperature of the steam must not be less than 60 degrees 
higher than the temperature desired in the kiln. 

The size of the steam supply mains will depend upon the volume of 
steam to be delivered, and the drop in pressure allowable. This may be 
determined with the help of the tables in Chapter XI in this book after a 
decision has been reached as to the total heat requirements of the kiln and 
the distance of the kiln from the source of steam supply. The SEtme prin- 
ciples apply for the installation of steam mains to the kilns as would apply 
for the installation of steam mains for any other pmpose. 

Extreme care should be given to the drainage of the steam main at the 
point of entrance to the kiln. It is advisable that water of condensation 
from the main shall be reheved from the bottom into the return and that 
steam for kilns shall be taken from the top of the main rather than to allow 
the condensation to drain tlirough the coils. The supply main may enter 
the kiln from a point above the coils used for heating, or from a point below 
them. The manner of providing for the drainage of these mains is shown 
by Figures 17-1 and 17-2. 

Manufacturers of drying equipment have devised nmnerous types of 
heating units but practically all have standardized on those constructed of 
pipe. The coils are placed either vertically along the side walls of kiln, or 
horizontally in a space provided underneath the material to be dried. In 
the latter instance they are usually installed in a horizontal position, although 
some manufacturers prefer coils placed vertically. 

Naturally, the problem of removal of air and condensation is not so 
great where small units are used. The advantage of more equal heat dis- 
tribution is claimed for the large unit laid horizontally, but this is not fully 
realized unless the removal of air and condensation is complete. Practical 
experience has demonstrated that incomplete removal of air and condensa- 
tion has not only caused unequal heat distribution throughout the kiln, 
but a drop in temperature of from 25 to 50 per cent. 

The types of heating units which are universally used and the manner of 
applying the Webster specialties for proper air removal and drainage of 
condensation are shown in Figures 17-3 and 17-5. These sketches and de- 




Fig. 17-2. Method of draining underground main 



Flo or L ine^j. 



Connect to 
Vacuum Return 



Fig. 17-1. Method of draining end of overhead main 

tails are self-explanatory, but attention is called to the necessity of providing 
dirt strainers to each drain connection to coils. These strainers should be 
of easy access for cleaning, as the temperature in kiln is usually high and dis- 
agreeable to work in for any length of time. 

Attention is caUed to the location of the drain traps. These should be 
readUy accessible also. Where thermostatic traps are used they should be 
located where they will not be subject to the high temperattn-es of the kiln. 
This is usually accomphshed by extending di"ain connections to the extreme 
front or rear of the kiln and placing the traps near the floor. 

On small units as shown in Figure 17-7, where thermostatic traps are 
used, additional provision for the removal of aii' is unnecessary, but where 
a lai'ge volume of condensation accumulates, additional provision for air 
removal is essential and heavy-duty traps should be used. Where the heat- 
ing unit is of the continuous-header type, as shown in Figure 17-4, the air 
removal can be accomplishd by the use of a heavy duty trap, equipped with 
a thermostatically actuated air by-pass within the trap. Where it is de- 
sired to drain the condensation from two or more coils to one heavy-duty 
trap, or where the return header of the coils is of special construction divided 
into two or more sections, and the condensation from aU sections is drained 
by one trap it is essential for the proper removal of air to equip each return 
header, or each section of the return header, with a thermostatically actuated 
return trap. The outlets of these traps are connected into the main vacuum 
return hne beyond the discharge connection of the heavy-duty trap, as shown 
by Figure 17-10. 

The discharge from all heavy-duty traps and thermostatically actuated 
return traps used in connection with kilns may be connected into a common 
return hne, but it is preferable that this return hne from kilns shall be ex- 
tended independently from the kilns to the vacuum pump, rather than to 
connect it into returns from the heating system of the manufacturing plant 

17—5 




Plan 



Slicatliiny^ 




WEBSTEn 
DIRT STRAINEB 

WEBSTER HEAVY 
Bypass , DUTY TRAP 



Rails for 
Transfer Truck 



^ZW^?^^77777^Z?7ZZ(7Mi 



Elevation 
Fii;. 17-3. Spclinns thrn a typical Dry Kiln with coils of the continuous-liiMdcr typo ii?inf;WolKtor Honv^- 

(Inty Traps for (lr:iin!ige 

17—6 



>.. 



.1. . . .' .~~1 . 



Steam Supply 



RETURN TRAP: 



Sectional Header C^ 



WEBSTER RETURN TRAP^ 



\lt 



21 



r 



Sectional Header 



^ 






Connect to 
Vacuum 
Return 



WEBSTER HEAVY 
DUTY TRAP 



Fig. 17-5. Typical section through a Dry Kiln using coils of the sectional-heMflcr type 



Fig. 17-4. Method of draining coil of continuous-header type 
witli r!r:iin connijctions on each end nf hi;ader. Detail of connection 
ut discharge entis of header. (See Fig. 17-3) 



WEBSTER 
RETURN TRAP 



V2' Linc^^ 



^ 



Sectional Header 



Coil Pipcs^ 



WEBSTER 
Gate Valve DIRT STRAINER 




Connect to 
Vacuum Return 



WEBSTER HEAVY DUTY TRAP 



Fig. 17-6. Cotiucctions around Wi^Iister Tfenvy-duty Trat) Drniiiing Coils with 
seclionai headers. (See I'^ig. T7-.'5) 



17—7 



Slieathing 




WEBSTER 
DIRT STRAINER 



Rails for 
Transfer Truck 



—WEBSTER 



% RETURN TRAP 



Elevation 




Plan 
Fig. 17-7. Sectional drawings of a typical small Dry Kiln using individual traps for drainage of coils 

17—8 



WEBSTER 

REfUnN 

rnAP 



WEBSTER 
REIUHN- 
TRAP 



WEBSTEf 

RETUnN 
TRAP 





Fig. 17-8. Showing the connections where two or 
more coils are drained through one Webster Heavy- 
duty Trap 



Fig. 17-9. Showing the connections where two or 
more coils are drained through Webster Return 
Traps 



.WEBSTER RETURN TRAP 




Connection from 
other Coils 



WEBSTER HEAVY DUTY TRAP 



Fig. 17-10. Detail of Connections around Webster Heavy-duty Trap 
(See Fig. 17-8) 

or other equipment. The condensation rate from the kilns will fluctuate, 
depending upon the temperature within the Jiiln, the nature and condition 
of the product being dried and the outside temperature. Consequently, 
at times when the air removal and condensat on rate from the kilns is high, 
trouble may be experienced with the operati:)n of other equipment if con- 
nected to the same return line. Also, if the same efficient equipment is not 
used in connection with the heating system or other equipment, as used in 

17—9 



connection with the kUns, the poor operation of the heating system or other 
equipnaent will naturally reflect in unsatisfactory operation of the kilns. 

The amount and location of radiation installed within the kiln will 
depend upon the location of the kiln, the temperature desired within the 
kiln, the steam pressure, and natiure of product to be dried. This con- 
stitutes a special branch of engineering and engineers thoroughly familiar 
with this class of work should be consulted. 

The method for figm-ing the total radiation required by a given dry 
kiln wiU not vary from the descriptions given in detail in Chapter V, except 
that during the warming-up period an additional heat factor is required to 
care for the moisture content of the lumber or other material being dried. 



17—10* 



CHAPTER XVIII 

Application of the Webster System to Railroad Terminals and 
Steamship Piers 

THERE 6tre many uses for thermostatically actuated return traps where 
the pressures carried are greater than in heating-system work. In- 
stances involving operation under steam gauge pressures of from 15 to 
100 pounds are described in this and following chapters. 

The requirement, in all cases, is that the return trap shall discharge 
the water and air of condensation without waste of steam and that the fix- 
ture being heated shall be maintained at maximum efficiency. 

In these special installations, certsiin fundamentals must be observed 
to secure successful operation. The first requires that the thermostatically 
actuated traps must discharge directly to the atmosphere or to a return line 
in which atmospheric pressure is maintained. 

This latter condition may be obtained by venting the return line free 
to the atmosphere. In some cases the same result is seciued by discharging 
the returns into a flash tank, the vent of which is connected to the low-pres- 
sure heating main, while the condensation is cared for through the usual 
type of retiu-n traps to the vacuum return. 

Railroad Terminals — One of the greatest causes of delay in the daily 
movement of hundreds of trains into and out of terminals where there is 
freezing weather is the difficulty in keeping the switches clear of snow and 
ice. 

Many terminals have therefore adopted the method (Figure 18-1) of 
placing steam-heating coils between the ties, under the switches. Due to 
the unusual exposure, these coils and their supply fines are operated under 
60 to 80 pounds gauge pressure in order to prevent freezing. The dripping 
of these lines and coils presents a double problem : First, the water and air 



c=^M=^ 




WEBSTER HIGH PRESSUR 
SYLPHON TRAP 



Sheel Steel fsstenei 
to Top and End ot 1 



Fig. 18-1. Special steam coil arrangement for prevention of freezing of railroad switches. 



18—1 



High Pressure 
Steam Line — 



WEBSTER HIGH PRESSURE- 
SYLPHON TRAP 



-Coverino 



Stand Pipe 




-Coverino 



■ ■ Disctiarge 
TC — to Waste 



Fig. 18-2. Method of prevention of freezing for fire protection 
lines. The water and steam pipes are encased in the same insula- 
tion and the steam pipe is drained by a thermostatic return trap 



of condensation must be 
freely discharged onto the 
roadlDcd, and Second, the 
condensation must not form 
steam clouds that might ob- 
scure nearby switch signals. 

A type of thermostat- 
ically actuated return trap 
which answers these re- 
quirements has been devel- 
oped by Warren Webster & 
Company after many tests 
and experiments. This re- 
turn trap is fitted with 
Monel-metal seats and valve 
pieces to withstand the wire- 
drawing effects of steam at 
high pressure differential. 
The thermostatic member 
is placed on the outboard or 
atmospheric side of the trap, 
and as the trap is generally 
placed in the rock ballast 
of the road bed, its exterior 
is usually given a special 
finish to give it protection 
against the elements. 

Railroad terminals are 
also equipped with exten- 
sive systems of water lines 
for fire protection purposes 
and these lines, too, must be 
kept from freezing. The 
method of prevention 
(Figure 18-2) found most 
carrying from 60 to 80 pounds gauge 



satisfactory is to run a steam line 

pressure, parallel with and close enough to each water fine that both 
steam and water lines can be encased in the same insulating covering. 
Where the water lines terminate, as at hydrant valve outlets, the same 
dripping of the steam lines and the same thorough removal of condensation 
with absence of steam cloud are required as with the yard switches. 

The same type of return trap is used in both cases. 

Steamship Piers — Steamship piers in cold climates are somewhat 
similar to railroad terminals in that the fire lines must be protected. In ad- 
dition, heat is required for a large number of small enclosures scattered 
throughout for housing the pier clerks. 

Piers are so constructed that the water of condensation from the coils 
heating the water lines and the clerk houses cannot be easily returned. 

18—2 



The practice is to discharge the condensation overboard through the deck of 
the pier. The return traps must, therefore, keep the lines clear of condensa- 
tion to avoid the possibility of freezing and at the same time avoid the waste 
of uncondensed steam. 

Webster Return Traps of similar construction to those previously 
described for railroad terminals are successfully used for this work. 



18—3* 



CHAPTER XIX 

Application of Webster System to Sterilizers, Cooking Kettles and 
Similar Apparatus 

HOSPITAL EQUIPMENT— All hospital equipment, such as steril- 
izers for surgical instruments, bandages and dressings, blanket 
warmers, etc., requires steam at more than the usual heating pres- 
sures. As these fixtures are comparatively small consumers of steam, being 
operated at gauge pressures of 15 to 100 pounds, and as they are situated 
at different parts of the building, it is usual to run a special set of steam 
supply and return Lines for them so that steam may be available at any time 
throughout the year. 

For the purpose of insuring rapid removal of condensation and air from 
each fixture, a Webster Return Trap of similar construction to those 
described in the preceding chapter is placed on the return of each unit. The 
operating temperature of the thermostatic members of these traps is close 
to that of steam at atmospheric pressure; hence it is necessary to provide 
sufficient exposed piping between the fixture and the trap to allow the con- 
densation to cool down to the operating temperature of the retiu-n trap. 
This exposed piping is termed cooling surface. 

Each return from trap before connecting into the common discharge 
line of similar traps should have a check valve between the trap and the 



Dressing Sterilizer 



Blanl<et Warmer Closet 




-Gate Valves 

~To Waste or Atmosphere 
^Dirt Pocket 
WEBSTER HEAVY DUTY TRAP 



Fig. 19-1. 



19—1 



Application of the Webster System to instrument sterilizer, dressing sterilizer and blanket 
warmer closet in a hospital 



Vent lu Heat Main 
"or Atmosphere 



High Pressure Drip 





High Pressure Trap 

Fig. 19-3. Method of discharging high-pressure drips 
or returns from high-pressure apparatus into lew -pressure 
heating mains and vacuum return mains through a Webster 
High-pressure Steam Trap 



Gate Valve 
Discharge Outlet*^ 

NO. 5 TYPE WEBSTER SYLPHON 
TRAP EQUIPPED WITH MONEL 
METAL VALVE PIECE AND SEAT 

Fig. 19-2. Connections for return trap 
where the operating pressure exceeds 15 
pounds per square inch 



return, as well as a hand shut-ofF valve between fixture and trap as shown in 
Figure 19 2. As stated in Chapter 17, where a common return line is used 
on such service to carry condensation from several traps, it is necessary 
that this line shall be vented free to the atmosphere, or in cases where pos- 
sible, to the low-pressure heat main (Figure 19-3). In no case should the 
discharge of these traps be connected directly to a vacuum return as the vac- 
uum would unbalance the operating member of the trap and cause it to give 
unsatisfactory results. 

Cooking Kettles, Plate Warmers, Bain-Maries, Coffee Urns 
AND Other Kitchen Equipment — This equipment requires practically 



Coffee Urns 




~6ate Valves 

-To Waste or Atmosphere 
- Dirt Pocket 
WEBSTER HEAVY DUTY TRAP 



Fig. 19-4. Application of the Webster System to kitchen equipment 



19-2 



il 



the same treatment as that of hospitals, and the same general statement 
about arrangement of return Knes applies. 

In food-product factories where the cooking equipment is much more 
extensive, a special form of Webster Float-controlled Return Trap with 
thermostatically actuated vent is used. This particular type is called the 
Webster High-differential Heavy-duty Trap. For details of these traps see 
Chapter 13, page 00. These traps are also used for removing the con- 
densation and air from the steam coils of vacumn pans in evaporating 
processes for sugar, milk salt, tartaric acid, candy, and the hke. 

It is important in all appUcations to high-pressure duty that the maxi- 
mum initial steam pressure to which the trap may be subjected does not 
exceed 50 lbs. gauge pressure, and that the maximum condensation rate 
sha J be known. 



19— 3* 



CHAPTER XX 
Applications of Webster Systems to Greenliouses 

THE heating of greenhouses is a special field, owing to the peculiar 
characteristics of the buildings and the necessity for even interior 
temperatiu'es. 

Commercial greenhouses are more exacting in their heat requirements 
than are public or private conservatories. Constant maintenance of the 
most desirable temperatures is essential in commercial houses to bring the 
crop to salable maturity in the shortest possible time and to keep the quan- 
tity of first-class product at a maximum throughout the season. A single 
serious temperature drop for a comparatively short interval may stunt the 
crop beyond recovery to normal condition within a month's time, and even 
slight temperature variation renders some kinds of plants more susceptible 
to certain destructive fungi. 

The heat regulation should to an extent be flexible, so that by applying 
more or less heat to compensate for loss of sunhght in cloudy weather the 
crop can be forced or retarded to come to matm'ity at the time when salable 
at the biggest profit. The blossoming of Easter lilies, for in&tance, requires 
absolute regulation to within a period of a very few days, and failure to 
meet the time limits results in an almost total loss. The same principle is 
utilized during the period of uncertain sunshine between November and 
February to keep the daily production of the majority of varieties of cut 
flowers more uniform. 

Due to the high rate of heat transmission through the glass of which 
greenhouse enclosures are largely made, the heating system must be capable 




Fig. 20-1. Conservatory of the Missouri Botanical Gardens 



20—1 




Fig. 20-2. Elevation oF half of houses A and B (see Fig. 20-3), Conservatory, Missouri Botanical Gardens- 
Other halves of these houses are symmetrical with the parts shown 

2a— 2 



of quick response to the demands for extra heat during nights, cloudy and 
cold days, and particularly when a sudden cold wind springs up. The 
system must also be capable of assisting the ventilators by quickly reducing 
the heat given off by coils, etc., during the days or parts of days when the 
heat from the sun's rays tends to increase the interior temperature beyond 
the point desired. 




Fig. 20-3. Plan of half the Conservatory of the Missouri Botanical Gardens, showing layout of heating coils 
20—3 



I 




Fig. 20-4. Fern House of the Missouri Botanical Gardens 




Fig. 20--^. I'loral Displiiy House of the Missouri Bolannical Gardi ns during < hrysantht^uuni show 
20—4 



i 



Fig. 20-8. I'iirl uf the power plant of the Davis Gardens, showing the feed-water healer and 
vacuum pumps of the Webster Heating System 

Up to within a comparatively few years ago, liot water was considered 
the best medium for circulation in the heating- coils of greenhouses. How- 
ever, as the size and importance of greenhouses have increased, a medium 
with quicker response in heat flow to better meet the many changes in out- 
side temperature and wind velocity and direction, has become necessary. 
Steam has proven ideal for this work when the conditions of the individual 
plant were understood. 

The arrangement of the heating coils in different types of greenhouses 
varies to suit the particular plants or vegetables grown and to meet the 
needs of forcing, propagation, etc. 

The Conservatory group of the Missouri Botanical Garden at St. Louis, 
Missouri, consisting of the Palm, Economic, Cycad, Succulent and Fern 
Houses, shown by Figures 20-1 to 20-5, are heated by the Webster Vacuum 
System of Steam Heating. These five greenhouses are part of the 125-acre 
Botanical Garden presented to the pubhc by Mr. Henry Shaw at his death 
in 1889. 



20—5 



I 




Fig. 20-6. 



One of the ten 600 by 80-ft. greenhouses of the Davis Gardens. 
Heated by the Webster Vacuum System 




Fig. 20-7. 



Crosswise view at the center of one of the cucumber houses of the Davis Gardens, 
showing arrangement of heating coils around the beds 



20—6 



Eleven thousand species of plants grow in this Garden. The Palm House 
contains 150 kinds of palms, such as date, cocoanut, sugar, Panama and 
rattan. The Economic House has a variety of tropical and sub-tropical 
plants, such as rubber, spices, drugs, dyes and coffee. The Cycad House is 
arranged in Japanese style and contains representatives of all known genera 
of cycads, as well as a collection of tropical evergreens. The Succulent 
House contains species of all the plants found in the deserts of the world. 
The Fern House has a very complete collection of the numerous ferns and 
their allies. 

Different atmospheric conditions are required in each of these Houses ; 
ferns, for instance, would not live in the dry air needed by the cactus. The 
Webster System is maintaining the required temperatures throughout every 




Fig. 20 9. Typicil temperature chart from one of the greenhouses of the Davis Gardens, Terre Haute, Ind. 

The outside temperature on the day the chart was taken averaged 28 deg. fahr. The variation in inside 

temperature was less than 3 deg. in 24 hours 

20—7 



peirt of these conservatories, and in most locations the permissible variation 
in temperature is limited to five degrees. How quickly the heating system 
must respond to sudden outside temperatiu-e changes to keep the interior 
temperature within the 5-degree variation limit may be inferred from the 
fact that the palm house is 60 feet high from floor to peak. 

The heating coils are banked on the side walls of the Houses as shown 
in Figure 20-2, and the arrangement of the coils is shown in plan, Figure 
20-3. Steam is supplied from a central heating plant under pressure and is 
reduced at the Conservatory, the heating system operating at from 1 to 
2 lb. gauge pressiu-e. The returns flow to the power house, where the main 
vacuum pumps discharge the condensation to an open tank, from which it 
is pumped to the boilers. 

The J. W. Davis Company, of Terre Haute, Indiana, operates the 
largest hothouse vegetable growing plant in the country, this plant con- 
sisting of ten greenhouses, each 600 feet long by 80 feet wide. Some idea 
of the magnitude of these houses may be conceived from the fact that for 
heating alone an 1800 h.p. steam generating plant and sixty miles of coils 
and piping are required. 

The main product of the Davis Company is hothouse-grown cucumbers, 
of which 12,000 dozen are shipped each week, but the output includes also 
flowering plants grown for the sale of both cut flowers and the plants them- 
selves. The stock of flowering plants, among other things, includes hun- 
dreds of thousands of cyclamen. 

The temperatiue requirements of these greenhouses are even more 
exacting than those of the Missouri Botanical Garden, as the chart. Figure 
20-9, taken from the recording thermometer, shows. 

The steam for heating is taken from a 95-lb. steam Une running through 
the connecting corridors, and the pressure is reduced in each greenhouse for 
the Webster Vacuum Heating System, which operates at 5-lb. pressure. 
The condensation is carried through a vacuum return back to the power 
plant, where it is delivered by the main vacuum pumps tlu-ough a tank to 
a Webster Feed-water Heater and from there pumped to the boilers. 



20—8* 



CHAPTER XXI 
Methods of Testing Return Traps in the Laboratory 

LABORATORY tests may be conducted for widely different purposes. 
J Those discussed in this chapter are the usual ones for determining 
the commerical efficiency of different types and makes of traps. 

AH of the operating conditions possible or probable in an actual heating 
system cannot be artificially produced in the laboratory, nor is it practical 
to carry out tests long enough or upon sufficient numbers of samples to learn 
all facts which become evident in practice. Furthermore, as the whole 
heatng system — its design and instaUation — has its effect upon the efficiency 
of the devices entering into it as parts, any laboratory tests for efficiency 
can indicate only the results which are probable when the devices are 
properly used in practice. 

Too much stress should not be laid, therefore, upon the comparative 
performances of any two makes of traps during laboratory tests. Knowl- 
edge of performances in actual instaUations of many heating systems, 
maker's abiUty and care in manufacturing, shop tests, inspection and proper 
engineering application of the traps are of great importance to the investi- 
gator who wishes to make commercial use of his study of such devices. 

However, as laboratory tests have their useful place in commercial 
investigation, tliis volume would be incomplete without descriptions of the 
following methods and apparatus which have been foimd practicable for 
reproducing as nearly as possible the conditions wliich exist in practice. 
Mention is also made of common but improper methods of testing which 
should be avoided because of the erroneous data which they produce. 

Usually the object of a laboratory test of a Return Trap is to determine 
one or all of the following characteristics : 

1. Effect of the trap upon radiator efficiency. 

2. Efiiciency of the trap for the removal of air and water of condensation 
and for conservation of the steam and vapor. 

3. Behavior of the trap without special adjustment to meet the varying 
coLditions of pressure and vacuum in normal practice. 

4. Durabifity of the trap through a long period of use. 

5. Construction features of the trap, particularly the amoimt of valve 
movement, which indicates the ability to get rid of dirt and pipe scale. 

The results of tests by many investigators, of radiator and trap effi- 
ciency, have varied widely and often been misleading, largely because the 
methods of testing have been faulty and partly because the devices them- 
selves have not always been manufactured to operate uniformly. 

Most tests of which the results have been published have been faulty 
through failure to cover a wide enough variety of test conditions, through 
limitation of the time period for each test to a few minutes instead of hours, 
and through considering and testing only one or two samples of any one 
device, instead of six or more selected by the investigator from the manu- 
facturer's stock bins. 

21—1 



Tests for Heating Efficiency: The lieating efficiency of a radiator 
depends upon physical conditions within the radiator which are affected by 
the action of the return trap. The radiator, among a number of common 
size and type, whicli maintains the highest average temperature when 
tested under the same conditions is the most efficient. 

The greatest possible steam economy is obtained where this efficiency 
is highest; that is, where steam is being condensed to the greatest extent 
possible within the radiator and the trap passes the least amount of steam or 
vapor into the return pipe. 

The highest radiator efficiency can be obtained only where the dis- 
charge is sufficiently and properly restricted to prevent steam from blowing 
into the return. Also the air released from the steam in the radiator must 
be aUowed to settle to the lower parts, from wliich it can enter the trap and 
be discharged. 

A return trap, in addition to restricting the discharge, must effectively 
accomplish the following: 

1. The discharge of all water of condensation as formed. Otherwise 
water accumulates in the radiator, prevents free discharge of air and also 
reduces the amount of surface effective for emitting heat from the steam. 

2. The discharge of all air as well as water from the radiator im- 
mediately upon their reaching the discharge outlet. 

3. Thorough prevention of the discharge of steam to the return. 

To accomplish these requirements the valve of a return trap must 
open or close within a very narrow range of temperature, above or below 
that of steam at pressure — irrespective of variations in steam pressure — 
and must adapt itself to such changes of pressure and corresponding steam 
temperature as may be met in practice. 

A brief review of the various types of return traps will facilitate a 
better understanding of tests and the results which are desired. 

All return traps commonly used in low-pressure or vacuum steam heat- 
ing practice may be classed as float traps, differential traps or thermo- 
static traps. 

Float Traps may have either sealed floats 

or inverted open buckets as the means of 

operation, and in either case, the float is raised 

by incoming condensation to uncover the valve 

seat through which water is discharged. Air 

escapes into the return pipe through an air 

^^ port, which must be located above the highest 

^1 water level in the trap. The air port is con- 

i troUed in some makes by thermostatic devices 

to prevent leakage of steam to the return. 

Tests upon a float trap may generally be 

expected to show considerable leakage of steam 

to the return unless the air port is thermo- 

Fig. 21-1 staticaUy controlled, or if the air port is so 

21—2 




controlled the small port and its mechanism may be vulnerable to the eflFects 
of dirt and rust. Such traps, however, will be found to have large water 
discharge capacities and some of the various makes can be used to advan- 
tage where widely varying volumes of water must be discharged without 
respect to temperature. 

A differential trap depends for operation upon the difference in pres- 
sure at the inlet and at the outlet. In its simplest form, it is a check valve 
which is closed when the difference in the pressures aliead and back of the 
clapper is insufficient to overcome the weight of the clapper, Inasmuch as 
no special means are provided for chscharge of air, such a valve may be ex- 
pected to leak steam to the return under any conditions of higher differential 
pressure and to stay closed with consequent 
air binding and water logging of the radia- 
tion where the pressure differential falls 
below that for wliich the valve is adjusted. 

Another form of differential trap is 
shown in Figure 21-2. Water entering the 
valve body raises the float, thus closing the 
air port by means of the valve piece attached 
to it. A higher pressure in the lower part 
of the trap B than that existing in the 
chamber A results in the operation of the 
piston wliich raises the valve from its seat 
l)y means of the connecting valve stem. As 
the condensation is discharged, the water 
level lowers and causes the float to fall, thus 
uncovering the air port, and equalizing the pressures on opposite sides of 
the piston. The weight of the operating parts and the force of the spring 
then closes the valve. This trap may be expected to show fairly good 
results in laboratory tests but it is not satisfactory under the usual operating . 
conditions in which dirt and scale are always present. 

A Thermostatic Trap depends for its operation upon the difference be- 
tween steam temperature at the pressure in radiator and the temperature 
of the condensate to which it is exposed. 

Many devices have been made which depend upon the expansion and 
contraction of metals or composition, or which make use of a Bourdon Tube. 
As a class these have failed because there is not enough difference in area 
between the inside and outside of the spring to produce the required force 
at normal difference in temperature between steam and air vapor at a given 
exterior pressure. Tliis and other faults, such as the necessity for adjustment 
for varying pressure conditions and slowness in operation, have led to the 
abandonment of thermostatic types by most manufacturers. 

Of all types of Return Traps, the only ones in general use today are those 
which depend for movement of the valve piece upon the change of vapor 
pressure of fluids confined within a flexible chamber when subjected to dif- 
ferent exterior pressures and temperatures. The volatile fluids contained in 
the flexible chamber vaporize to a greater or less pressure depending upon the 

21—3 




Fig. 21-2 



temperature of the steam, vapor, water or air which surround the chamber. 
The exjjansion or contraction of the chamber moves the valve piece wliich 
is attached to the free end of the chamber. 

These traps are, generally speaking, of either the "inboard" type where 
the thermostatic meinber is exposed to the temperature and pressure of the 
steam, water and air as it exists at the radiator outlet, or of the "outboard" 
type which depends for operation upon the conditions existing between the 
valve piece and the entrance to the return piping beyond the trap. 

To be effective for the inboard type, the thermostatic member must 
expand and contract through a distance sufficient to open and close the 
valve under the influence of the extremely small differences of temperature 
which exist during normal operation. Most traps of the inboard type are 
inefficient because of the very short "stroke" which can be realized with the 
inelastic disc construction generally utilized for the flexible chamber, this 
defect showing in operation as inabiUty of the trap to rid itself of dirt and 
scale. 

Traps of the outboard type are affected by the pressure and temperature 
of the return. They are in proper adjustment only at one definite pressure 
and temperature and out of adjustment at all other normal combinations of 
pressure and temperature. They cannot be adjusted even for these normal 
var'atlons in radiator pressures and vacuum in the return, and as a result 
Usually water-log and air-bind the radiator by staying closed when high 
temperature and pressure differentials exist, or stay open and blow steam 
under conditions of low differential. 

The Webster Sylphon Trap shown in Figure 
21-3, has best met all of the requirements of 
theory, test and operation during the years since 
its first use in practice. 

It is a thermostatic trap of the inboard type 
and as such is affected in operation only by the 
temperatures and pressures existing in the 
radiator. 

The multifold design of the thermostatic 
member or Sylphon Bellows gives it great elas- 
ticity and consequent ample movement in re- 
sponse to changes of temperature and pressure in 
the medium surrounding it. 

The Webster Sylphon Trap is filled with a 
liquid which makes the trap self-compensating for 
differences in operating pressures of steam within 
the radiator. It operates effectively and without adjustment to rid the 
radiator of water and air and to prevent discharge of steam, whether the 
pressure differential between radiator and return is 3^ lb. or 15 lb. per in. 

Its construction, using a conical valve piece closing upon a sharp-edged 
seat, assures positive self-cleaning. Dirt and scale cannot lodge between 
the valve and seat to cause the trap to leak steam to the return. 

Because of careful workmanship and frequent factory tests and inspec- 
tion, Webster Sylphon Traps in laboratory tests of a number of units may 

21—4 




Fig. 21-3. The Webster 
Sylphon Trap 



be expected to show very uniform results — in fact, so uniform that successful 
operation of these traps in large numbers in any properly designed heating 
system can be foretold from the laboratory results. 

The Webster No. 7 Trap is constructed with a different form of flexible 
member but its operating characteristics are essentially identical with and 
fully as satisfactory as those of the Webster Sylphon Trap. 

It has been stated that a trap must not leak steam to the return, but 
in this connection there should be no confusion between steam discharged 
through a trap and vapor rising from hot condensate. Though their ap- 
pearance during certain forms of visual tests are much alike, they are two 
entirely different things, and if confused with each other, as is sometimes 
done, wrong conclusions will result. 

Visibihty is deceptive. A great amount of moisture in the atmosphere 
and favorable hght conditions both add to the visibility. The air dis- 
charged from an efficient trap is saturated with water at discharge tempera- 
ture and this water mixing with air at room temperature looks like steam, 
while the discharge of a trap utterly deficient in air removal shows only the 
vapor of re-evaporation. 

The water of condensation contains total heat in excess of that in water 
of condensation at lower pressure. This excess heat boils off some of the 
condensation into steam. The amount so boiled off is entirely dependent 
on excess of total heat in outflowing condensate above total heat of water 
at lower pressure. 

If steam passes out with condensate, a steam of greater total heat is 
dissipated. A fuUy efficient trap releases the condensation at or near steam 
temperature and radiator pressure, into a return of lower pressure. AU 
heat above that consistent with lower pressure then generates vapor. This 
vapor passes to the vapor receiver in a test. A certain amount of vapor 
per pound of condensation is normal and any excess of vapor above the 
normal is steam leakage. 

The condensate from a higher pressure into a lower pressure will never 
be at a higher temperature than that due to steam at the lower pressure. 
The balance of the heat in the outflowing condensate wiU flash part of the 
water into steam. 

These points are emphasized to show the falhbility of visibility test to 
show the efficiency of return traps. 

Very rough tests, Figure 21-4, are often made by connecting a trap to a 
radiator, letting it discharge to the atmosphere, and noting its operation. 
With this test particularly, the erroneous distinction between the vapor 
from steam and from re-evaporation often leads to a wrong conclusion. 
Further, such a test can show only how the trap behaves for a condition 
far different from those of actual operation. The effects of the return 
piping connections and the pressure conditions therein have such a great 
effect upon operation that the results of rough tests of this nature should 
never be accepted as conclusive. 

Tests of similar apparatus are often made to determine the comparative 
value of two traps, using the amount of water discharged from each trap 

21—5 



i 




Fig. 21-4. Visibility test showing at the left a trap which is di ?chariring condensation without steam leakage, 
and at the right a trap in which steam is leaking through the outlet valve 

after runs of equal duration as a measure of their desirability. In such cases 
the condensate dripping from the trap is carefuUy weighed. 

It is evident upon consideration that such tests demonstrate nothing 
regarding the performance of the traps while no water is held up in the radia- 
tor, and even then there is no assurance that the same comparative result 
will be obtained when the trap is under actual operating conditions. 

Other tests have been made to determine the vacuum which could be 
maintained at the discharge end as a criterion of the comparative worth of 
traps. For such tests, the apparatus consists of a radiator, a return trap, a 
return connection to a vacuum pump, and devices for mainteiining constant 
pressure of stccun supply to the radiator and for operating the pump at a 
constant speed. 

The trap with which a higher degree of vacuum is maintained by this 
test is considered to be the better. With httle or no attempt to determine 
the extent to which the radiator is air- and water-bound in the comparative 
tests, the data obtained has frequently led to a wrong choice and unsatis- 
factory results when the trap was operated in a heating system. 

21—6 




21—7 



These few devices and methods are the ones commonly used for de- 
termining comparative worth of retm:n traps where only the most easily 
procm'able testing apparatus is available. Like other scientific investiga- 
tions more careful methods will lead to more reUable results and with proper 
apparatus and thoughtful procedure it is entirely practicable to obtain test 
data which can be relied upon as accurately forecasting the success wliich 
may be expected from the use of any return trap in an actual heating system. 

The first thought for any rehable test should be to create laboratory 
conditions as nearly as possible like those met in actual practice. Coinci- 
dently, the apparatus should be designed to provide exactly like and 
simultaneous test conditions where traps are tested for comparison, and of 
course, applicinces for measuring the results must be carefully placed and 
adjusted. Then, by following a proper test, planned to exhaust the various 
possibihties of different operating conditions, results are secured whicli can 
be accepted as conclusive. 

A complete testing outfit is illustrated in Figure 2 1-5. Sets of two radia- 
tors are installed exactly alike, so that the operating conditions for com- 
parative tests of any two traps are as nearly the same as possible. 




Fig. 21-6. Showing position of thermometers for determining internal conditions 
at various parts of the radiator 



21—8 



The test radiators should be: (1) of the steam type to provide most 
difficult conditions for trap operation, (2) of height normally met in practice, 
and, (3) of a size approaching the maximum capacity of the trap at the mini- 
mum pressure diflferentied contemplated for the test. 

Each radiator is provided with thermometers set in wells, as shown 
in Figure 21-6. Three thermometers in the loop at the supply end, three in 
the loop at the center, and three in the loop at the return end of each radiator 
give a fair enough indication whether or not air is present in any portion of 
the radiator. 

The water gauge glass with connections tapped into the highest and 
lowest parts of the last loop of each radiator, serves to show whether water 
accumulates in the radiator, and if so, the amount, or whether the trap freely 
discharges all water of condensation. 

Pressure gauges, preferably mercury columns, are connected to each 
end loop to show the pressures at both supply and return ends of the radia- 
tors. The average pressure and temperature must be known to determine 
the heating efficiency. 

The apparatus must be sup- 
' plemented with other devices, as 
will be described later if a com- 
plete test is desired. However, 
- I where part knowledge quickly 

gained is acceptable, indication 
of the following characteristics 
of return traps can be obtained 
by using only the twin radiators: 

A. Ability to discharge all 
water of condensation, as indi- 
cated by the water glass. 

B. Effectiveness in discharg- 
ging all air, as shown by the ther- 
mometers. 

C. The time required after 
turning steam on the cold radi- 
ator before the radiator is com- 
pletely heated throughout. 

D. The rate of condensation 
for the radiator itself after it is 
completely heated, or the rate of 
discharge of the trap can be de- 
termined by weighing the con- 
densate collected during a meas- 
ured period. 

All of the data refers of 
course to the action of the traps 
with steam at the average pres- 
sure 'n the radiator and discharg- 
ing direct to atmosphere. The 




Fig. 21-7. Arrangement of bucket calorimeter for 
determining the quantity of trap discharge 



21—9 




Fig. 21-8. Twin measuring apparatus for determining 
separately the amount of discharge from each 
of two radiators 
21—10 



results obtained will vary great- 
ly from those of test conditions, 
mon6 closely approaching actual . 
operation.' 

^ determination of the' 
amount of steam or vapor as 
well as of water discharged, 
through a trap can be made by 
attacliing a comparatively sim- 
ple bucket calorimeter, as shown 
in Figure 21-7. The discharge 
from the trap condenses in the 
coil and discharges to and ;is 
mi^^ed with the water in the 
bucket. 

The observations in such a 
; test; are: 

; Time of run. , 

Barometric pressure. 

Steam pressure. 

Temperatures of water at 
beginning and end of test. 

Weight of water before and 
after test. 

The "heat balance" calcu- 
lated from this data will show 
whether steam has leaked 
through the trap; that is, the 
increase in B.t.u. in the cooHng 
water should indicate only an 
amount accountable for by the 
absorption of latent heat from 
the steam condensed in the coil. 

Figure 21-8 illustrates a 
form of apparatus for twin oper- 
ation in combination ^ith the 
two radiators for separately 
measuring the water and vapor 
discharged from the return 
traps. 

The discharge from each 
trap is led to a separating tee, 
from which the v^ater passes 
downward ' through a seal into 
the measuring vessel, the air 
and vapor rising to the condens- 
ing coil and thence to another 
tank in which the condensed 
vapor is measured. 



The tanks which collect water are large enough for a run of an hour or 
more, are provided with gauge glasses and scales, have pipe connections at 
the top leading to a dry vacuum pump, and have the necessary drain and 
pet cocks for breaking vacuum when emptying the tanks. The smaller 
tanks are provided with similar equipment and connections. 

Thermometers and mercury columns are installed, the former to give 
the necessary temperature readings from each tank of water, and the latter, 
readings of the vacuum at which the test is being run. 

Connection is made from the outlet of each trap to the separating 
tees by means of steam hose. This connection and all pipe connections from 
the tanks to the pump must of course be absolutely tight, as air inleakage 
would impair the results by carrying water to the condensing coils. All 
metal piping at ends of steam hose must be covered with wool felt or similar 
non-conductive material. 

The steam pressure at 

the inlets of the radiators is [ ■ ][■ 1^ '^ Hftgij^ " ] 

kept constant by means of 
pressure - reducing valves 
and the pump vacuum by 
means of vacuum - pump 
igovernors, as shown in Fig- 
ure 21-9. 

Very complete tests of 
return tramps can be made 
w^ith this apparatus, and 
results will closely approxi- 
mate the operating charac- 
teristics of the same traps in 
actual heating service. 

Complete testing of 
traps involves the following 
considemtions: 

1. Selection of trap. 
The traps to be tested should 
be selected from the manufacturer's stock bins, or if this is impractical they 
should be purchased on the market. 

2. Number of traps to be tested. A fair determination of the average 
performance of any make of trap requires that at least six units, or more if 
possible, be placed under the same test conditions. Only by this procedure 
can the standard of performance be determined within reasonable limits of 
uniformity. 

3. Dvu-ation of each test. The first two traps of any given make under 
any given pressure and vacuum conditions should be tested during a run of 
at least five hours. Subsequent tests may be shortened to as little as one 
hour, depending upon the time taken in the earlier tests for the traps to 
show all of their operating characteristics. The longer time for first tests 
ha"* been found by experience to be justified by the failure of certain types 
of traps to show their deficiencies within a shorter period. 

21—11 




Fig. 21-0. Pressure-reducing valves for maintaining constant 
pressure at radiator inlets during test 



4. Pressure and vacuum conditions. Each trap should be tested 
under each one of the following combinations. 

1 lb. pressure in radiator and 5 in. vacuum in return. 

5 " " " " " 5 ■■ 

10" " " " " 5 

1 " " " " " 10 

5" " " " " 10 

10" " " " " 10 

1 15 

5 " " " " " 15 

10" " " " " 15 

These combinations are frequently met in practice, the higher pressures 
and vacuums representing unfavorable conditions, such as small sizes of 
supply pipes, small Ufts or small piping in the return. 

5. Frequency of readings. Usually the thermometers, water gauges, 
barometer, pressure gauges, etc., need be read only at intervals of 5 to 10 
minutes after the radiators have become thoroughly heated. Where two 
traps are tested on the twin apparatus, corresponding instruments should 
be read simultaneously. 

At the conclusion of the test, the data is worked into terms of efficiency 
and capacity of the traps. 

The heat efficiency is the relation expressed in per cent of the average 
temperature throughout the radiator to the temperature of the entering 
steam. To obtain average heat throughout the radiator, it is usual to add 
the temperatures shown by thermometers in the end loops only once, while 
the temperatures in the center sections are given added value by being con- 
sidered twice. In other words, if there are nine thermometers as shown in 
Figure 21-6, the sum of the temperatures is divided by 12 to obtain the 
average. A low heat efficiency indicates either air- or water-binding or both. 
If no water shows in the radiator gauge glass at time of low efficiency, it 
may be safely assumed that the return trap is not successfully ridding the 
radiator of air. 

The relation of the weight of condensed vapor collected in the smaller 
tank of Figure 21-8 to the total weight of condensate and condensed vapor 
collected in both the smaller and larger tanks is the "vapor efficiency" of 
the trap. Corrections for re-evaporation may be made if desired, but when 
tests are run with low pressure in the radiator and low vacuum in the return, 
the correction factor may be neglected without appreciable error. 

Where the gauge glass shows that the trap is holding condensation in 
the radiator, the condensation should accumulate during entire test period. 
The condensation is then drawn into the larger condensate tank (Figure 21-8) 
by creating a vacuum there by shutting steam from the radiator and open- 
ing an air vent on the radiator. The weight of water actually passed by the 
trap during the test period compared as a percentage to the total of water 
passed during test, plus the water accumulated in the radiator is the "water- 
discharge efficiency" of the trap. 

Tests along the lines indicated, and with apparatus described, provide 
practically all the data which is usuedly investigated, although other useful 
and important data may be obtained with additional equipment. 

21—12 



k 



For instance, it may be de- 
sirable to determine the maxi- 
mum discharge capacity of a 
given trap when operating at 
stated pressure differential. This 
pressure may be the one at which 
the trap is to be operated in a 
proposed heating system, and it 
may or may not be the pressure 
diJBFerential which the manufac- 
turer has selected as a basis for 
rating his trap. 

Such tests must take into 
consideration the fact that with 
thermostatic traps, the temper- 
ature of the condensate has a 
major effect upon the rate of dis- 
charge. As the temperature of 
the condensate in an actual in- 
stallation is comparatively high, 
it is specially desirable that ap- 
paratus used for determining 
flooded capacities of traps shall 
provide for suitable heating of 
the water to be discharged. 

Such apparatus is illustrated 
in Figure 21-10. The tank is 
"closed" and is provided with 
steam injection devices for heat- 
ing the water to any desired 
temperature. In addition to 
water head, discharge pressure 
can be placed upon the trap by 
compressed air. The water when 
discharged falls into a second 
tank which is open to the atmosphere, and from which it is returned to the 
supply tank by means of the pump. 

This apparatus makes possible the determination of the proper rating 
for any trap in pounds of water per unit of time for any pressure differential 
or any condensate temperature which may be met in practice. 

Another interesting test, designed to indicate the ability of a trap to 
rid itself of the dirt and scale met in operation in a heating system, can be 
made with the apparatus shown in Figure 21-11. In this test, a mixture of 
cylinder oil and core sand, sifted through a 1/10 in. mesh screen, is inserted 
at the tee in the outlet piping, in doses of usually about a quarter teaspoonful. 
Upon opening the valve in the outlet connection, the mixture passes 
to the trap and its effect upon operation is carefully noted. 

21—13 




Fi^. 21-10. Apparatus for determining flooded capacity 
of traps 





I 



Fig. 21-11. Apparatus for determining the ability of a trap to rid itself of dirt and scale 

A repetition of this dosing with dirt about ten times gives a fair test for 
the trap. The number of times out of the ten in which the trap closes and 
opens properly to hold steam and to discharge air and water indicates the 
aoility of the trap to operate efficiently under the trying conditions of dirt 
and scale which are most serious during the initiation of a new radiator or 
newly erected heating system, 

A vibrating machine driven by a motor for demonstrating the relative 
durability of the thermostatic members of return traps is illustrated in 
Figure 23-12. The stroke of the machine can be adjusted to equal the 
distance through which the thermostatic member will expand and contract 
during operation in a heating system. A counter for determining the number 
of strokes is provided. 

The trap using the member wliich will withstand the greatest number 
of strokes through its individual distance of operation, before failure of the 
material occurs, is the one likely to have the longest life in actual service 
before repairs are required. This test gives merely indication of the durability 
of the trap. Other operating conditions besides the movement of the 
member affect the wearing qualities, but unfortunately, these conditions 
cannot readily be duplicated in short-time laboratory tests. 

21—14 




Fig. 23-12. Vibrating niacbine for demonstrating the relative durability of various types of thermostatio 

members of retiu-n traps 

Enough has been said to show that vahiable data regarding the probable 
perfomaance of return traps can be obtained in the laboratory where suitable 
appEu-atus is available and where suitable test methods are carefully applied. 
However, the long-time test of devices in actual heating systems is the best 
guide for determining the relative value of return traps, and further, the 
efficiency of a good return trap can be fully reahzed only when the heating 
system itself is properly planned and operated. 

Re-evaporation: The idea which seems to prevail that water at a 
temperature higher than the boihng point of the space into which it is dis- 
charged should not make steam when so discharged is erroneous. 

The amount of steam so generated is readily determined by the chart, 
Figure 21-13, provided the initial temperature of the water and the pressure 
of the space into which it is discharged are known. 

Many times highly efficient radiator traps are condemned for leaking 
steam, due to the observed vapor of re-evaporation noted at their discharge 
outlet, and less efficient traps have been commended because of absence of 
such vapors. 

The absence of vapor at the discharge is in reality an indication that the 
trap is holding back condensation and entrained air until the temperature 
of the discharge is materially less than that of steam at the pressure of the 
outlet. The consequence of such holding back is a partially air-bound emd 
water-logged radiator, with less than fuU efficiency in the radiation. 

Again, there are instances where in tests of radiator trap efficiency all 
the steam leakage recorded has been ascribed to re-evaporation when, due 
to high differential of initial and terminal conditions, all or a greater part of 
the observed steam should have been ascribed to re-evaporation. 

21—15 




Fig. 21-13. Re-evaporation chart for determining the percentage of water re-evaporated from any tem- 
perature between 300 and 170 deg. f ahr. into water vapor of a lower temperature and corresponding pressure 



21—16* 



i 



CHAPTER XXII 
Installation Details 

MANY of the methods of pipe connections which have been developed 
by Warren Webster & Company dm-ing the past thirty-three years, 
and which have become standard practice, are shown in this chapter 
and elsewhere in connection with descriptions of specific apparatus. Most 
of the ones previously illustrated as Webster Service Details are famUiar 
to the profession and trade. These drawings, which indicate the general 
arrangement of the pipe, fittings and Webster apparatus, when used, have 
been revised from time to time and as shown here represent the latest and 
best thought. They are not to be used as exact layouts of piping, as each 
individual application presents its own special conditions. No effort has 
been made to indicate the necessary unions or right and left nipples required 
for the connections, as these requirements for any case would naturally 
be best determined by the detail of the layout or by the steamfitter at the 
job, based upon his skill and upon materials available. 



Details Applicable to Both the Webster Vacuirm System and the Webster 
Modulation System 



Heatina Main 




-Rise to new leveL, 



f ~^ — Rise to I 



Reducing Tee- 



-, WEBSTER CLASS"B 
3 DIRT STRAINER 
Reducing Gale Valve 
FlanQe 





WEBSTER CLASS "t 
DIRT STRAINEfl 
Reducing 



Provide at least 3-0 
Qf pipe cooling surlaci 
between drip point and 
q return trap connect into top-^ 

or side ot return main 




Gate Valve 

WEBSTER HEAVY DUTY TRAP- 
Set trap on bracket support J 
on foundation or on lloor-^ Connect into 
top or side of 
return main 



Fig. 22-1. Application of a Webster Return Trap 
on a low-pressure heat main, at a low point where 
the main rises. A, sufficient length of uncov^r^d pips 
must be pro ided between the drip point and the 
return trap. 



22—1 



Fig. 22-2. The drainage of a low-pressure heat 
main at a low point, where the line rises, is of such 
importance that special attention is warranted. 
This diagram shows a large main with drip through 
gate valve, Webster Dirt Strainer and Webster 
Heavy-duty Trap. 



By-pass with Globe or Anole Valve 



Live Steam from Boiler 




Receiver 3" Pipe 24" lono - 



Tee for Gauoe Connectfon 






Straiaht Pattern Pressure 
Reducing Valve - 



-Gate Valve 

Provide Pet Cock for Venting Diaphragm 
^^Connecl to Receiver 



I 



G^^ 



PluQoed Tee 



Fig. 22-3. Connections for a steam pressure-reducing valve. The control pipe from the low-pressure 
side of the line must be taken from a point far enough from the valve to insure that the pressure will have 
been fully expanded. The use of the receiver facilitates a constant static pressure on the diaphragm of the 
reducing valve. 




— 7 lo' 

Relurn Main-^ '; 

Beducer-^-*ffl^ 



1}4 Pipe uncovered- 





Fig. 22-4. Method of dripping supply risers Fig. 22-5. Three methods of making loops to 
through a Webster Return Trap into vacuum return provide for expansion movement in risers. The ex- 
line; the vertical leg acts both as cooling surface and pansion of supply and return risers should have 
dirt packet. careful study. 



Up to Radiator 




Dirt Pocket ~^J-J, 



Fig. 22-7. Arrangement for drip- 
ping a down-feed riser into an over- 
head return main, shovving the un- 
covered horizontal cooling pipe. 



-Supply Riser 




Fig. 22-6. Arrangement 
for dripping the end of a sup- 
ply main which also carries 
the condensation from the up- 
feed risers. Overhead return 
main. The return trap is lo- 
cated at a point four feet or 
more from the point dripped. 



WEBSTER 
RETURN TRAP 



22—2 



Fig. 22-8. Dripping the 
heel of a down-feerl supply 
riser, where proN'ision must 
also be made for down thrust 
or expansion. 



Fig. 22-9. The end of an 
up-feed system supply main 
where provision must be 
made for the drip as well as 
the condensation from the ris- 
ers. The return is located 
along the floor and the ver- 
tical line to return trap can 
be used as a cooling leg. 



J^ — Supply Riser 



Fig. 22-10. Arrangement for drip- 
ping down-feed riser-; into an overhead 
return line. Cooling pipe used with a 
Webster Dirt Strain t located at the 
entrance to the return trap. 







Overhead Return Maifix, 



Fig. 22-11. Arrange- 
ment for dripping the end 
of an overhead supply 
main through Webster 
Dirt Strainer and Return 
Trap into an overhead re- 
turn main. 



22—3 




WEBSTER RETURN TRAP 
Plug 



Steam Supply Main 



Fig. 22-12. Arrangement for drip- 
ping both riser and main where an up- 
feed riser is fed from the bottom of a 
supply main. A vertical cooling leg is 
used. 



Ceiling 



Steam Supply Main 



Fig. 22-13. Arrangement of connec- 
tions where the up-feed riser is fed from 
the top of the overhead supply main 
and the return main is also overhead. 
A vertical cooling leg is used. 



WEBSTER RETURN TRAP- 
Plug- 



Supply Riser 




Birt Pocket 
Cap 



Return Riser ,-=, 



Supply Riser 




Untuvered Pipe 
not less than 3'O'lona 



Din Pocket 
> -Cap 



Fig. 22-14. Where it is not possible to run a vertical cooling leg on the drip of the riser, cooling surface 
in the form of a horizontal pipe may be employed as shown. 

22-^ 




Dirt Pockel 



WEBSTER RETURN TRAP 



Fig. 22-15. Drip of main and up-feed riser using horizontal cooling surface. 



Fig. 22-16. The drip of the end of a 
branch supply main which also carries 
the drip of down-feed risers. A Web- 
ster Dirt Strainer is used in place of a 
dirt pocket. 




fl Belurn Riser vi,eb8tei, MODULATION VALVE 



Fig. 22-17. Showing provision 
for expansion on a down-feed 
riser and the method of dripping 
through Webster Dirt Strainer 
and Return Trap. 



WEBSTER 
DIRT STRAINER 



Fig. 22-18. Arrangement of 
connections to a radiator where 
the branch run-outs are in the 
floor construction. 



i^ Return Main at Floor 




WEBSTER . 
RETURN TRAP 



22—5 



^=5^=in 



Heating 
RIsei-H 



e-None of the Piping siiown 
on this detail to be covered 




Connect to Return 



rig. 22-19 A. small amount of heating surface is 
often desired in certain classes of buildings in bath 
rooms, etc., without invoKing the expense of sep- 
arate radiators. Where these rooms are one above 
the other a heating riser may be used with connec- 
tions as shown in this diagram. 



Supply Riser 




Low Pressure 
Steam Supply 
Main 



-t-Uncovered 
Pipe 




WEBSTER 

DRIP TRAP 

Increase 

one pipe 

size at 

lirsi fitting 



Fig. 22-20. The dripping of the end of an over- 
head steam supply main where the return line is 
carried along near the floor. The uncovered ver- 
tical line to the return trap acts as a cooling leg. 



Supply Riser WEBSTER MODUUTION VALVE 

/ Bushing 



Return^ 
Riser 



_Watcr Pattern 
Radiator 




Fig. 22-21. Arrangement of connections to a 
radiator in a factory or loft building where there is 
no objection to branch runK)uts on the ceiling of the 
floor below. 




Fig. 22-22. Arrangement of coimections to a 
radiator with all branch run-outs exposed in the 



22—6 



Supply Riser- 



WEBSTER 
MODUUTION VALVE 




Fig. 22-23. Arrangement for removing a considerable amount of condensation from a down-feed riser. 
A. drip goes through a Webster Dirt Strainer emd Return Trap, the connection to lowest radiator being 
made above the drip point. 



^^ManitQld Coil 



Above Method for Coils ^ 
of not over 1 Pipes 

iVa' Short Nipple 
Reducing Tee' 
Dirt Pocket — 
IV2 Nipple, 6"long 



^Manifold Coll 



Above Method for Coils/ 
of 1 1 Pipes or over 

1',4'Short Nipple 
Reducing Tee 
„ Dirt Pocl(et 
IV2 Nipple, 6"long'' 




Connect into Top 
of Return Main 



Fig. 22-24. Drip connections to the return head- 
ers of manifold coils. Coils of ten pipes or less have 
one return header and those of over ten pipes are 
usually split and provided with two headers. 

22—7 



Fig. 22-25. Arrangement of headers similar to 
Fig. 22-24, but showing the use of the Webster Dirt 
Strainer at the entrance of the return traps. 



"} Pn r^ PI r~*^ P* 




Bottom Outtot Manifold 



WEBSTEB RETUBN TB«P 



PLAN 
BOTTOM OUTLET MANIFOLD 



M 



Bottom Outlet Manifold 




Gate Valve' Q ^WEBSTER 

' DIRTSTRAINEB i 
PLAN 
BOTTOM OUTLET MANIFOLD 



KIpple, maximum sizi 



Nipple, maximum sizi 



@@@@@@ 



ELEVATION 
END OUTLET MANIFOLD 

Drop Leg 



_ Reducing Ell, 
bushed 11 necessary 
WEBSTER RJDIATOR 




Reducing Ell, 
bushed If necessary 

OIRTsfRAnER WEBSTER RADIATOR 
JJini binsiMtn JND COIL TRAP No,7 




Fig. 22-26. With drop leg to catch dirt. 



Connecl Into return 
main ot riser 

Fig. 22-27. With Webster Dirt Strainer. 



Return connection to a flat overhead coil where (above) a bottom-outlet manifold and where (below) 
an end-outlet manifold is used. Dirt is collected by drop leg (Fig. 22-26) or bv a Webster Dirt Strainer 

(Fig. 22-27). 



ManlloliJ 
Coil 




Retlucino 
,EII 






Manifold 
Coil 



Reducing 
Elk 




Fig. 22-28. With drop leg to catch dirt. 



Fig. 22-29. With Webster Dirt Strainer. 



Wide, flat, overhead coils should have return connections taken from both ends of the return manifold. 
Dirt is coUected by a drop leg (Fig. 22-28) or by a Webster Dkt Strainer (Fig. 22-29). 

22-8 



Fig. 22-30. Arrangement for profitable use of the heat 
in the condensation from a heating system. The conden- 
sation is passed through the coils of an auxiliary water 
heater and its heat so transferred to water for domestic or 
manufacturing use. 




Note — ^Additional details applicable 
to the Webster Modulation 
System will be found on 
page 00. 



Hot Water Generator 




^^- 




Hot Water Inlet 
to Generator 



Auxiliary Heater 



H CoJd Water Inlet 



-Pipe Standard Support^ 



Floot 



Details Applicable to the Webster Vacuum System Only 




Q Q. 



Fig. 22-31. Under certain conditions the condensation from the heels of down- 
feed risers can be removed by connecting the separate gravity drip or wet-return line 
to the return inlet of a Webster Feed- water Heater. In this instance, the static head 
between the top of the heater and the lowest radiator connection must exceed the 
pressure in the heater. Suitable connection of the return line to the heater is shown 
in the diagram. 



22—9 



Supply 
"Riser 



Heating Supply Main^ 



Wei Return 
Union -^^ jJ^=A Close to Floor 



Overhead Vacuum Return 




WEBSTER HEAVY-DUTY TRAP 



<--WEBSTER 
LIFT FITTING 



Ttiis Pipe to be same size 
as tnlet to Trap 



/Gate Valve Ao Drain 



Floor Line^ 



Fig. 22-32. Where the drips of risers and mains are carried through a separate gravity drip 
Une near the floor and it is desired to deliver the condensation into the overhead vacuum return 
line through a Webster Heavy-duty Trap, the arrangement shown has proven most satisfactory. 



Fig. 22-33. In the usual down-feed system where the drips of risers are cared for by a separate 
gravity drip line run near the floor and where the condensation is to be delivered to the overhead 
vacuum return line through a Webster Heavy-duty Trap, the method shown should be followed^ 



22—10 



I'ig. 22-34. The usiml method for rcmovr.l cf c6n- 

liensation from a group of not over 22 sections of 

Vento radiation supplied with steam at each end is to 

provide a drip connection also at each end as shown. 

In some instances, however, where the pressure i.s low 

or more than 22 Vento sections are used, one of the 

return lines should be extended 

through the Vento bushing and 

to about the center of the group, 

so that air-binding will be 

avoided. 



Steara Supply 
"CoiuiecUons 



Blast Healej- Seclloos 



WEBSTEfl .RETURN TRAPS 



Drip Connections 
same as shown 
tor opposite Side 



I 




Gate Valve- 
■WEaSTEB" OIRT STRAIN EB > 

WESSTtB HEAXi fiUTY TRAP, 



Fig. 22-35. The approved method of 
draining condensation from the coils of 
a hot-water service heater to the 
vacuum return line through gate valve, 
Webster Dirt 
Strainer and Web- 
ster Heavy - duty 
Trap. 



22—11 



Fig. 22-36. Arrangement for removal of 
eonde'nsniion from a group of not over 14 
seel inns (if \ento radiation, where the supply 
steam enters one end of the group and the 
returns are taken from the opposite end. 
The return of each group is separate, the con- 
densation being carried through a common 
return line to the \\ Clistir I Ic,ivy-duty Trap, 
and I he air from each group 
— Blast Healer Sections handled separately 
through a Webster Syl- 
phon Trap connecting to 
a common discharge line 
to the vacuum return line. 



WEBSTER RETURN TRAPS 




Vacuum Air Line 



Fig. 22-37. Arrangement of piping where a vacuum 

^'i-^^^i^^^ return line is carried along the wall near the floor and 

^^ passes doorways or other openings. The water is car- 

^ ried under the opening and the air is passed through 



I — I , I , — ^T I y-^XyyJ^ lieu uiiuei Lue upeiiiiig t 

f{^;<;/;;«c%^/,i.»5>i5^;5i^^ the line over the opening. 



Plugged Tee. 



Line of Trench 
Under Doorway 



Plugged Tee 



22—12 



Details Applicable to the Webster Modulation System Only 



Supply Riser or 
Supply Connection 
to Radiator 




This Connection'/2 when Air Line Valve is 
1 0' 0"or less from Dry Return Branch or 
Main and 3/4 when over 10' 0''distanl / 



Ceiino Line 
y2"wtLlSTER RETURN TRAP. 
'/2 Socket 



Supply Main must be . 
Run Full Size to Drip 
Point Connection 



Drop Leo — n 




Drip to Wet 
Return at end ^ 
of Run in Main 



Reducino Tee 



Union above 
Water Line 
of Boiler 



Water Line of Boiler^, 



Connect into Wet- 
Return Main 



Wet Return near Flooj;, 
with space t)eneath for 

Cleaning 



C 



1> 



Fig. 22-38. Where a drip is required, at 
the end of a heating main, the air should 
usually be vented through a Webster Syl- 
phon Trap into the dry return, as shown 
in this diagram. 



Pig. 22-39. The dry return in a Webster Modulation 
System, due to its required grade, must sometimes get 
down into the head room, in which event it may be 
drained into the wet return and elevated to a higher 
level. Certain fundamentals must be obsers'ed in do- 
ing this. The most important is that at the point 
wliere the change in elevation occurs, the dry return 
must never be closer than 6 inches to the level of the 
inlet to the Webster Modulation Vent Trap. 

22—13 



WEBSTER RETURN TRAP 
Above hiflhest point of — 
Dry Return 




30" or more if possible 



Union 



This Connection must Special Swtno 
be on same Centre as Chert Valve 

Wet Return ^^\ \ 



i^h 



Supply Main 



Fig. 22-10. There is 
often a demand for hot 
water for domestic sup- 
ply where this water 
can best be heated by 
transfer of part of the 
heat from the conden- 
sation in the steam 
heating system. The 
diagram shows one method of doing this in connec- 
tion with a Webster Modulation System. The hol^ 
water heater and storage tank should be located close 
to the steam boiler so that the steam supply will be 
available when the plant is being operated at very 
low pressures. 



Water Line of Boiler- 



'Return from Hot Water Generator. Connect to Wet Return 



Wet Return near Floor 



be: 



X. 



Floor Line^^ 



WEBSTER RETURN TRAP 



Ceiling Line-^ 




Grade Radiator 1 in 1 
toward Wet Returo end 



Supply Main 



^ 




Fig. 22-41. Connections for overhead radia- 
tion in basement, where there is sufficient drop 
for gravity flow between the radiation and the 
water line of the boiler. 



Water Line of Boiler- 



^^peclal Swing Check Valve 
^^■^^^Tn'is Connection must be on same 
( f center as Wet Return y'Wet Return near Floor 



-Q Floor 



22—14 



WEBSTER RETURN-»H1 — n npi, 

TRAP, above Hiohest "Ug-D 4y 1/2 Air Line 

Poinl ol Dry Return [ff|.Couplino 71*" ^Connect into Top of Return 



Supply Line 



1/2 Air Line - 



Fig. 22-43. Radiation must sometimes 
be placed on the side walls of basements, 
where steam can be circulated only by pro- 
viding sufficient head for gravity flow be- 
tween the radiator return outlet and the 
water line of the boiler. The arrangement 
shown handles this problem well. 




This Connection must 

be on same Center as 

Wet Return 

\ Special Swing 

I Check Valvel 



Return from Radiator 
Connect to Wet Return. 



Wet Return near Floor 



N 



/ 



22—15* 



CHAPTER XXIII 

Appliances for the Webster Systems of Steam Heating 

W TEBSTER Appliances used as parts of Webster Heating Systems 



W' 



are illustrated and briefly described in the following pages. 
These appliances include : 



Webster Oil Separators Webster Modulation Vent Traps 

Webster Grease and Oil Traps Webster Damper Regulators 

Webster Dirt Strainers Webster Expansion Joints 

Webster Return Traps Webster Pipe Anchors 

Webster Heavy-duty Traps Webster Hydro-pneumatic Tanks 

Webster Double-service Valves Webster Low-pressure Boiler Feeders 

Webster Lift Fittings. Webster Conserving Valves 

Webster Suction Strainers Webster Hylo Vacuum Controllers 

Webster Vapor Economizers Webster Hylo Vacuum Traps 
Webster Vacuum-pump Governors Webster High-pressure Traps 
Webster Air-separating Tanks and Webster High-differential Heavy- 
Receivers duty Traps 
Webster Modulation Valves 

Webster Return Traps for Automatically Removing Water of 
Condensation and Air from Heating Units: The return trap, to be per- 
fect in operation, should — 

(a) AUow the condensation to escape at a temperature sKghtly below 
that of the steam. 

(6) Drain the radiator thoroughly by gravity, without the assistance 
of pressure or vacuum. A water-logged radiator loses efficiency because 
part of the heating is being done by the water condensed from steam, which 
is at lower temperature, and because a water-logged radiator is also an air- 
bound radiator. 

(c) Permit continuous removal of air. An air-bound radiator loses 
efficiency because the steam cannot completely fiU it. 

(d) Automatically close to prevent loss or waste of steam. 

(e) Work within the widest necessary range of pressure and vacuum 
variation. 

(f) Require no adjustment under such variations. 

(g) Be noiseless in operation, if used in rooms where noise is objection- 
able. 

(h) Be so designed that the valve will close even when dirt may be 
present in normal quantities. 

(0 Be durable and require little or no attention or repairs. 

The efficiency of the radiator will depend upon how nearly the return 
trap meets these requirements. 

A return trap working sluggishly will not only hold back the water, 
but will "bottle up" the air and air-bind the radiator, thus defeating the 
very purpose of a vacuum system. 

As different methods must at times be employed in connection with 
23—1 



100% RADIATOR EFFICIENCY 



SUCCESSFUL 
OPERATION 
AT VARYING 
PRESSURES 

^^1 




NO INTERFERENCE BY DIRT WITH THE PROPER FUNC- 
TIONING OF TRAP 



AUTOMATIC REMOVAL 
OF AIR AND WATER 
OF CONDENSATION 
WITH NO LEAK- 
OF STEAM 



99.5 PLUS PER CENT 
VAPOR EFFICIENCY 



Fig. 23-1. The requirements of a perfect radiator trap. 

direct radiators, blast sections, riser drips, main drips, dripping hot-water 
generators, factory coils, etc., Webster Return Traps are made in several 
forms, at least one of which will meet the requirements of any installation. 
The type and capacity of the trap required depends upon the point of 
application, the amount of air and water to be removed, the character of 
the heating surface and the pressure and vacuum carried. Suggestions as 
to the proper sizes of traps for specific conditions will therefore be of value 
and freely given upon request. 

The. Webster Sylphon Trap 

The Webster Sylphon Trap has been specially designed to meet the 
requirements for a perfect radiator trap. It maintains the highest possible 
efficiency within the heating surface by the removal of all of the products of 
condensation, and as this is effected without loss of steam, it is economical 
in the highest degree. The economy is especially apparent when reduced- 
pressure five steam is used in whole or in part, or where under present 
operating conditions it may be necessary to waste large quantities of cold 
water to cool the heating system returns before they enter the vacuum 
pump. 

The operating member consists of a Sylphon beUows, which carries a 
conical-shaped valve piece, closing against a sharp-edged seat. The bellows 
member is supersensitive, operating to close or open the valve port by the 
slightest change in the temperature of the surrounding medium, and is the 
most durable form of thermostatic device so far known. The multiple 
construction of the seamless brass folds forming the bellows distributes the 
strain of movement and increases the life of the operating member. The 
increase in the pressure on the outside of the bellows is compensated by the 
increase in pressure on the inside of the bellows. 

23—2 



I 





Fig. 23-2. No. 512 Model H Webster Sylphon Trap. Size of pipe connections, H-inch. 



* 





. ■;A 



Big. 23-3. No. 522 Model H Webster Sylphon Trap. Size of pipe connections, J^-inch. Nos. 512 and 522 

differ in capacity rating and lift of valve, No. 522 being of greater capacity. 
No. 523 has same size body mechanism and capacity as No. 522, but has J^-inch pipe connections to meet 

unusual specifications in that respect. 

The sensitiveness of this member is due to the flexibihty of the waQs 
of the bellows to movement in the desired direction and the small amount 
of movement of each fold when acted upon by the pressure surrounding and 
also that generated within the beUows. The sum of the small movement 
of each of the many folds gives a greater total lift of the vedve than any other 
device for similar purpose. 

The conical valve piece and sharp-edged seat give increased capacity 
for discharge of water, and the valve does not become inoperative due to 
presence of dirt and scale. 

The Webster Sylphon Trap will close quickly and positively when steam 
reaches the beUows, while the water and air will be freely withdrawn or dis- 

23—3 





Fig. 23-4. No. 533 Model H Webster Sylphon Trap. Size of pipe connections, ^-inch. 

No. 534 Has same size body with 1-inch pipe connections to meet unusual specifications. 
No. 544 Similar, but larger throughout for 1-inch pipe connections and greater duty. 
No. 545 The largest in proportions and capacity. For IJi-inch pipe connections. 

charged at sKghtly below the temperature of the steam at the existing pres- 
sure. 

This means that every radiator in use will be thoroughly efficient in 
heating, .as there will be no "pocketing" of air or "bottling up" of water 
within the radiator. 

As the valve is full open when cold, the radiator will be fully drained 
when steam is turned off, and the vacuum condition existing in the return 
line will extend within the radiator, assisting circulation when steam is 
again turned on. 

Operation : As the steam first flows into the cool radiator, it expels the 
contained air and initial condensation through the wide-open trap. As the 
radiator warms up from inflow of steam, the bellows commences to expand, 
but remains partially open as long as the air and water in the trap are at a 
lower temperature than that of the steam. The moment the air is entirely 
expeUed from trap body, and replaced with steam, the valve closes. It 
opens again when water and air at a temperature slightly less than that of 
the steam accumulate in the trap. Then, as the water and air escape and 
are replaced in the trap body by steam, the trap again closes, thus complet- 
ing its cycle. 






Model H 
Angle 



Model G 
Straightway offset 



Model R 
Right comer 




Fig. 23-5. Bodies of Webster Series S Sylphon Traps. 



23- 



Table 23-1. Models and Dimensions of Sylphon Traps 

For convenience in meddng pipe connections, Webster Series 5 Sylphon Traps of the smaller sizes are made 
with four types of bodies as shown. Model H or angle is the one most used. 



I 



Size 


Trap Nos. 
& Model 


A 


B 


c 


D 


H" 


512H 


3" 


IH" 


1}^" 


^Vs" 


y^' 


522H 


3Vs" 


Wi" 


lA" 


5M" 


H" 


523H 


SVs" 


2" 


1^" 


5M" 


w 


S33H 


4A" 


2^" 


IM" 


5V8" 


1" 


534H 


m" 


2%" 


IK" 


5M" 


1" 


544H 


4A" 


2^" 


2" 


6W' 


IH" 


545H 


41^" 


2^" 


2" 


6M" 



Size 


Trap Nos. and Model 


A 


B 


c 


D 


'E 


K" 


512G, 512R or 512L 


3" 


IH" 


1" 


iH" 


iH" 


H" 


522G, 522R or 522L 


SVs" 


m" 


m" 


5H" 


1%" 


H" 


523G, 523R or 523L 


ZVs" 


i«" 


m" 


5ft" 


m" 


H" 


533G 


4ft" 


2ft" 


IH" 


5%" 


Not 


1" 


534G 


4H" 


2ft" 


m" 


6" 


made 



For ratings, see Chapter 13, page 00. 



The Webster No. 7 Trap 



Webster No. 7 Traps also realize all of the requirements for thoroughly 
satisfactory operation as radiator traps. They are apphed at the outlets 
of steam radiators and coUs, at drip points on steam supply lines and risers 
and at the outlets of blast sections on fan coils and provide continuous 




Fig. 23-10. Exterior and interior of No. 722 Webster Trap. 



23-5 



free and thorough removal of entrained air and water of condensation, 
without permitting any live steam to escape to waste in the return hnes. 

The inlet of the trap is attached to the radiator, coil or supply Line by 
means of the imion connection, and the outlet is piped into the return line. 

The diapliragms, wliich form the active part of the operating member, 
are built of four successive phosphor-bronze plates instead of the usual two 
and for that reason there is greater diaplu-agm movement and the valve 
has greater lift than usually found in traps of similar types. 

The expansion and contraction of the diaphragm member is produced 
by differences in volume and pressure of a hennetically-sealed fluid charge 
in response to changes in temperature. Even a very slight temperature 
change produces a powerful force to actuate the conical valve piece, which 
in closing, fits tightly on a sharp-edged seat. 

No part of the valve mechanism is impaired by normal quantities of 
the scale and dirt that collect in steam-heating systems. 

Table 23-2. Models and Dimensions 
of Webster Series 7 Traps 

For convenience in making pipe connectionsj. 
Webster Series 7 Traps are made with four types o 
bodies as shown. Model H or angle is the one 
most used. 



Size 


Trap 
No. 


A 


B 


c 


D 


E 


y>:' 


712H 


314" 


1t^" 


1**" 


m" 




y?:' 


722H 


3^" 


liV" 


1%" 


3A" 




H" 


723H 


3^" 


1t^" 


m" 


3fk" 




w 


733H 


m" 


VA" 


2%" 


4t%" 




1" 


744H 


Wa" 


2" 


2K" 


4A" 




iM" 


745H 

712G1 


m" 


2" 


2H" 


4A" 




V2" 


712RI 
712L 

722G 


3M" 


2H" 


M" 


3A" 


2H" 


H" 


722RI 
722L 


m" 


2M" 


¥4!' 


3M" 


2M" 



For ratings see Chapter 13, page 00. 



23—6 



I 
I 





Fig. 23-15. No. 522 Water-seal Trap 
The Webster Water-seal Trap 
This is an older design of automatic balanced valve, requiring no ad- 
justment. It is suitable for blower apparatus and for basement main drips 
and for draining coils in factory installations. 

It passes the maximum quantity of condensation, hot or cold, and at 
the same time relieves the heating unit of air, without waste of un- 
condensed steam. 



Table 23-3. Models and 
Dimensions 



For convenience in making 
pipe connections, Webster Water- 
seal Traps are made with four 
types of bodies, which have the 
same characteristics as the four 
body type, for Webster Sylphon 
Traps as shown on page 23-4 





MODELS G R and L 






Size 


A 


B 


c 


D 


E 


>^"-512 


3" 


1>^" 


1" 


4M" 


ly?." 


}«"-522 


W^' 


\%" 


IM" 


5?8" 


l^s" 


?4"-523 


iy%" 


m" 


IK" 


5^" 


m" 


M"-533 


4i^" 


2^" 


IH" 


5M" 


Not 


l"-534 


^y^•' 


2A" 


IM" 


6" 


Made 




Fig. 23-16 



J4"-522 

M"-523 

^"-533 

l"-534 

J "-544 

lii"-545 



iVs" 


m" 


lA" 


4,%" 


Wb" 


2" 


1-^" 


4^" 


ih" 


2ys" 


Wi" 


53/g" 


Ws" 


m" 


IM" 


5il" 


4A" 


2^" 


2" 


6H" 


4^" 


2^" 


2" 


6ii" 




For ratings, see Chapter 13, Page 00 



Fig. 23-17 



23—7 



Webster Heavy-duty Traps 





Fig. 23-18. Series 19T Webster Heavy-duty Trap 
with thermostatically-controlled air by-pass. 

Series 19T with Thermostatically- 
controlled Air By- pass. For 15-lb. 
Maximum Operating Pressure : — The 
Webster Heavy-duty Trap handles un- 
usually large quantities of conden- 
sation, and is for dripping main supply 
risers or main entering or leaving the 
building, for draining large sections 
of blower coils or pipe manifolds, for draining hot-water generators, etc. 

Insofar as the discharge of condensation is concerned, this trap operates 
on the float principle and has a large water outlet to get the condensation 
away as quickly as possible from the unit to be drained. 

Air is eliminated by means of a thermostatically actuated by-pass, as 
shown in Figure 23-18. The operating device, the valve piece and seat are 
the same as used in the Webster No. 7 Trap. 

The body is of cast iron, as is also the cover, which is bolted on, easily 
removable and so designed that all interior parts are exposed for inspection 
upon its removal. The outlet is in the bottom of the body, and the inlet 
may be on either end, with the opposite opening plugged. It is recom- 
mended that wherever practical the inlet farthest away from the valve be 
used. An opening is provided at the bottom of the float chamber as a clean- 
out by-pass and for draining the trap when out of use. 

The float has ample leverage to avoid sticking of the valve. The cone- 
pointed valve and square-edged seat prevent accumulation of dirt where it 

23—8 



might clog the port. The valve is water-sealed at eiU times, as the water 
level is always well above the seat. The float lever is kept within the ver- 
tical plane of action by guide flanges cast into the trap body. 
For dimensions, see page 000 





Fig. 2a-19. Series 19-H Webster Heavy-duty 
Trap with hand-controlled air by-pass. 

Series 19H with Hand-Controlled Air 
By-pass. For 15 lb. Maximum Operating 
Pressure: — This type of Webster Heavy- 
duty Trap is essentially the same in con- 
struction and is applied for exactly the 
same operating conditions as the Series 
19 T Trap before described, but is de- 
signed to meet a requirement for manual 
adjustment of the air vent. 

As shown in Figure 23-19, the air port is controUed by means of a con- 
ical valve closing upon a sharp-edged seat. The amount of air leakage is 
controUed by the use of a wrench in backing the valve off its seat as much 
as necessary or advisable. In all other respects the construction is identical 
with that of the Series 19 T Trap. 

For dimensions, see page 000. 

High-Differential Type Series 20, for Working Pressures up to 50 lb. per 
sq. in.: — The Webster High-differential Heavy-duty Trap is recommended 
for steam pressures higher than 15 pounds and where large quantities of 
condensation may be discharged. It is particularly apphcable to problems 
like or s imil ar to those described in Chapter 16. 

23—9 




Fig. 23-20. Series 20 Webster High-differential Heavy- 
duty Trap for workins; pressures up to 50 lb. per sq. in- 



The trap body is constructed of 
, cast iron and has an easily removable 

cover of the same material. The valve 

is of the balanced type and operates 
lagainst a monel-metal seat. The ball 

float is extra heavy to withstand the 

higher pressures. 

The Webster High-differential 
Heavy-duty Trap may be operated with 
a constant leakage through a hand- 
adjusted air vent, though the best prac- 
tice calls for control of the air dis- 
charge by means of a thermostatically 
actuated valve in a by-pass of pipe and 
fittings as shown in Figure 23-21. 





Fig. 23-21. Conventional arrangement of Series 

20 Webster High-differential Heavy-Duty Trap 

and Webster Dirt Strainer (Inlet pipe may be 

connected to opposite end if desired.) 



23—10 



Table 23-4. Dimensions of Webster Heavy-duty Traps 





Drain Openino 

Fig. 23-23. Series 19H 



A=Size , 
Outlet f 



Drain OpeninQi 
Fig. 23-22. Series 19T 




«=Size Outlet). 



Fig. 23-24. High-differential 
AH dimensions in inches and subject to slight variation. 



Number 


A 


ai|bIc d|e|f|g|h 

Series 19T, with thermostatically controlled by-pass. 

1 1 1 "^1 1 ■' 1 


u 


V 


w 


0019-T 


V^ 


^4 


13M 


1 


7Ji 


12J^ 


41/^ 


31^ 


2y?, 


9V8 


55/^ 


J^ 


019-T 


% 


■a 


15M 


1 


8 


15 


m 


•m 


2% 


103^ 


6 14 


H 


119-T 


lii 


1^4 


19^ 


iH 


9 


18^ 


5% 


•m 


41/s 


lOM 


7 


1 


219-T 


2 


2 


20^ 


m 


10}^ 


^9% 


6^8 


m 


m 


12M 


8 


1J4 



Series 19H, with hand controlled by-pass. 



0019-H 


H 


H 


13M 


1 


7^ 


12J^ 


41/^ 


31/^ 


2V,. 


lOiA 


5=/^ 


1^ 


019-H 


■H 


V4 


15M 


1 


8 


15 


41/s 


3i/s 


2y, 


107^ 


614 


^4 


119-H 


lii 


IH 


19^ 


m 


9 


18?^ 


5»/s 


3^8 


iH 


12 J^ 


7 


1 


219-H 


2 


2 


20^ 


1^8 


lOJ^ 


19K 


6^8 


4^8 


m 


14?^ 


8 


ly^ 



Series 20, High-differential type. 



020 


H 


H 


15?^ 


1 


8 


15 


m 


3H 


2% 


12M 


6M 


H 


120 


IM 


IH 


19 J^ 


1^/8 


9 


18^ 


5^8 


3'^8 


41/8 


13^ 


7 


1 


220 


2 


2 


205^ 


l^i 


lOH 


19% 


6>^8 


4^8 


4M 


14J^ 


8 


lyz 



2^—11 





Fig. 23-25. The Webster Type W Modulation Valve. 
The Webster Type W Modulation Valve 

The Webster Type W Modulation Valve is a special-purpose radiator 
valve of the quick-opening, non-rising stem, straight-Uft type, built for com- 
plete opening or closing with less than a single turn of the handle. Its 
manipulation is as simple and its control as eflfective as the movement that 
regulates light from a gas jet. 

As the name implies, the principal function of the Webster Modulation 
Valve is to facilitate "Modulation" of temperature in each room according 
to the desires of the occupant, by varying the amount of steam admitted 
to the radiator or coil. A pointer attached to the handle travehng over a 
graduated dial indicates the amount of valve opening at all times. 

With the valve full open, the discharge capacity through the ports is 
equal to that of the outlet connection of the valve. 

Less than three-fourths of the valve lift and opening movement is re- 
quired to produce modulation up to normal full heating requirement. The 
rest is in reserve to admit more steam diu-ing the heating-up period, as needed 
to compensate for the higher condensation rate caused by contact with the 
cold radiator and its surrounding air. 

Construction Details: The modulation effect is produced by a pat- 
ented hmiting sleeve (see Figure 23-25) which varies admission of steam in 
progressive volume with the lift of the valve piece. 

A Jenkins disc is used to insure tight closing. With the exception of 
this and the handle, all parts are of brass. The handle is of special composi- 
tion and so formed that the hand of the operator does not come into contact 
with the heated surface of the valve body. 

Application: The Webster Modulation Valve may be used on either 
hot-water type radiators (having connections from section to section at both 
top and bottom) or with steam type radiators (bottom connections only), 
although the former type is preferable. 

Where the Webster Modulation Valve is used with the hot-water type 
of radiator, it should be placed at the top to bring the operating handle in 

23—12 



the most convenient location and to permit the steam to circulate across 
and downward. The air and condensation, being heavier, fall to the bottom 
in advance of the steam and give full efficiency to the part of the radiator 
heated. 

Where the Webster Modulation 
Valve is used with a steam type radia- 
tor, or placed at the bottom of a hot- 
water type radiator, the response can- 
not be so quick with the Modulation 
Valve or with any other type of inlet 
valve for that matter, because some 
air is temporarily pocketed in the {ar 
sections. This air must find its way 
out through the return trap before fuU 




Fig. 23-26. Typical application of the extension 
stem principle. 




Fig. 23-27. Typical appli- 
cation of chain attach- 
ment to Webster Type W 
Modulation Valve. 



23—13 



efficiency is possible. As the inlet connection is always at the bottom of 
the steam type radiator, the Modulation Valve must be there also; a com- 
paratively inconvenient position for operating. 

If placed at the bottom of radiators, because other connections cannot 
be arranged, the inlet bushing should be eccentric and so located that the 
center line of the radiator inlet is above that of the radiator outlet. This is 
essential to prevent condensation from draining by gravity through the sup- 
ply instead of the return connections, thus eliminating water-hammer. 

Extension Stem: For attachment to radiators concealed in recesses or 
under window seats behind grilles, the Webster Modulation Valve is provided 
with an extension stem and a special dial that may be placed on the face, top 
or end of the grille or seat (see Figures 23-26) . 

The stem has a universal joint on each end, which permits operation 
of the valve from a point not directly in line with the valve stem, and at 
the same time provides enough play to avoid sticking or binding from any 
misahgnment or shifting caused by expansion and contraction. This 
construction also avoids the difficulty of making very accurate stem con- 
nections. 

The outside indicator dial, pointer and handle are similar to those used 
on top of the standard valve. 

Chain Attachment: The Webster Modulation Valve to be applied to 
radiators or coils located in skylights, overhead, or on walls neai the ceiling, 
can be fitted with a chain attachment for convenience in obtaining every 
advantage of the modulation f eatiu-e (Figures 23-27 £uid 23-28) . 

The chain wheel is substituted for the handle of the standau-d type of 
Modulation Valve and the chain is made just long enough to permit easy 
grasp from the floor. Tags are attached to the lower portion of the chain 
in such positions that the end hanging at the bottom indicates the degree of 
valve opening. 




Table 23-5. Dimensions of Type W 
Modulation Valve. 



Size 


A 


B 


c 


D 


V2 


2J^ 


1% 


2% 


4^ 


H 


3M 


W2 


2y% 


47^ 


1 


Ws 


Wi 


2% 


m 


IM 


3M 


2 


2% 


6ys 



Fig. 23-29. 



All dimensions in inches and subject to slight variation. 
For ratings, see Chapter 13, page 00. 



23—14 




Fig. 23-30. The Webster Double-Service Valve. 



The Webster Double- Service Valve 

This is one of the latest developments of apparatus for simplifying 
piping connections in steam heating systems in certain types of construction. 

Common practice in buildings of only one story and in some other 
instances calls for a steam supply line along the ceiling of the first floor to 
feed each radiator or coil through a short down-feed riser, which must be 
dripped into the retmn line. This multiplicity of unsightly connections is 
simplified by the use of Webster Double-service Valves, apphed in the 
manner shown in Figure 23-31. 

This valve performs "double service, " as a supply valve for the radiator 
and as a trap for draining the riser. 

The thermostatically controUed valve is open, when there is water or 
a'r in the riser, and permits the condensate to flow through a by-pass in the 
valve body into the radiator and thence to waste. Upon the presence of 
steam the thermostatic member expands, closes the valve, and thus prevents 
waste of steam. 

Steam is admitted to the radiator in the amount desired, by means of 
the quick-opening valve, which is provided with a graduated dial and 
handle. This is not a Webster Modulation Valve, as the valve disc is 
designed for the special feature of quick opening without respect to modu- 
lating effect. 

The valve body is best-quality cast iron, and aU other parts except the 
valve disc and handle are brass. Nuts and nipples are provided at each 
connection to promote easy installation. 

The thermostatic member, which is built up of four discs of phosphor 
bronze and fiUed with a volatile fluid, the conical valve piece and the sharp- 

23—15 



j^Supply Main 



fe 



Supply Riser-s> 



I 



All Connections to be taken 
from Bottom of Main 



edged seat are of standard pat- 
tern as used in the Webster No. 7 
Trap. 

The inlet valve is provided 
with a ring seat and Jenkins 
disc, to insure tight closing. Its 
quick-opening feature is pro- 
vided by a screw stem of such 
pitch that the valve will be com- 
pletely opened with less than a 
complete turn of the handle. 



WEBSTEH 

DOUBLE SERVICE 

VALVE 




Fig. 23-31. Application of a Webster Double-service Valve to a standard cast-iron radiator. 




Fig. 23-32. The Webster Double-service valve 
Table 23-6. Dimensions of Webster Double-ssrvice Valves in Inches. 



Size 


A 


B 


c 


D 


E 


F 


G 


H 


J 


M 


3M 


1 


2J^ 


5V8 


Wi 


2M 


^% 


10 


Vs 


1 


W% 


IM 


23^ 


Wi 


w% 


3 


3V8 


lOJ^ 


Vs 


IH 


4 


Wi 


Wi 


6M 


IH 


w% 


iVs 


11^ 


Vs 


W2 


Wi 


Wi 


2ys 


8 


\% 


w% 


4 


12^ 


H 



23—16 



Webster Oil Separators 

Webster Oil Separators of the standard types for removing cylinder 
oil, grease, etc., from cmrents of exhaust steam have steel multi-baffles, 
formed by a number of hooked plates interposed to the flow of the steam 
in a way to cause separation by impact, by change of direction and by adhe- 
sion. There is no unobstructed path through any Webster Oil Separator, 
yet the free area through which steam must pass is several times greater 
than the area of the inlet and outlet, thus minimizing the pressure loss due 
to friction. 

The use of these separators protects boiler heating surfaces and interior 
siuf aces of heating systems from the oil deposits that otherwise seriously 
impair heat transmission and often cause serious damage. 

These separators may also be used for such specied purposes as removing 
moisture or oil from compressed air and other gases. 



WEBSTER OIL SEPARATOR 



Exhaust 
Main 



To Heating Supply Main 

Size of Vent to correspond .vilh Size 
of Tapping in top of Grease Trjp 

WEBSTER GREASE AND OIL TRAP 




Fig. 23<33. Method of connecting a Webster Grease 

Tlcap to a Webster Oil Separator, \rhere a partial 

vacnommay at times be carried on 

the heating main. 



Size of vent to correspond 
witit size of tapping in^op of 
crease trap ^'^'-^ 



Gate V^lve: 



A 




This distance from 
bottom of oil separatuf 
to the Inlet of grease 
trap must be at least 
five feet 



fig. 23-34. Typical method of draining Webster Oil 
Separator through a Webster Giease Trap. 



23—17 






Fig. 23-35. Standard Horizontal. 
Sizes — 2 to 6-inch. 



Fig. 23-36. Standard Horizontal. 
Sizes — 8 to 16-inch. 



Fig. 23-37. Vertical, for either 

ascending or descending currents. 

Sizes — 3 to 16-inch. 



Table 23-7. Maximum Ratings of Oil Separators in Pounds per Minute at 
Average Gauge Pressures Based Upon a Pipe Velocity. 
of 6000 Feet per Minute. 







PRESSURE LB. PER SQUARE INCH 




Size 





S 10 


15 


2 


5.2 


6.7 8.4 


10. 


3 


11.4 


15. 18.6 


22. 


4 


19.8 


26. 32. 


38. 


5 


31. 


40.6 50.2 


59.7 


6 


45. 


59. 73. 


86.5 


8 


78. 


102. 126. 


150. 


10 


123. 


160. 200. 


235. 


12 


176. 


231. 285. 


339. 


14 


222. 


292. 361. 


427. 


16 


294. 


385. 475. 


565. 


18 


375. 


492. 608. 


720. 


20 


452. 


595. 735. 


870. 


22 


550. 


725. 900. 


1060. 


24 


660. 


870. 1070. 


1270. 



For lower velocities, the pounds carried will be proportional as the Iowct velocity is to 6000. 
25—18 



That Webster Separators are efficient in all their standard and special 
forms is indicated by absolute satisfaction in over 15,000 installations. 

The material ordinarily used in the shells is close-grained cast iron, but 

special shell of semi-steel, cast steel or other material can be furnished at 

extra cost. 

Table 23-8. Dimensions of Webster Oil Separators. 

All dimensions in inches. Weights are approximate and do not include companion flanges, which are 
furnished only as extras and at extra cost. 





Fig. 23-38. 



Fig. 23-39. 



HORIZONTAL STANDARD TYPE 



Fig. 






Dimensions 








Flanges 


















No. & 




Size 


B 


D 


G 


L 


Drip 


Out. 
Diam. 


Bolt Sizes 
Circle of 
Bolts 




2 


lOH 


10 


SV?. 


6 


K 


6 


4M ir-Vs 


o 


3 


15M 


13 


IVA 


6M 


Va. 


7^2 


6 4^% 


i 


4 


n% 


15 


13^ 


ay?. 


1 


9 


'!V2 8-% 


5 


185/, 


15?/s 


14^/8 


8^/8 


1 


10 


8J^ 8-M 




6 


19M 


16 


U'A 


9H 


1 


11 


9^ 8-M 




8 


21?^ 


ITA 


18 


loy^ 


1J4 


131/2 


llM &-K 


o 


10 


22 V^ 


1914 


18H 


12^/8 


m 


16 


U}i \2-y8 


S 


12 


24H 


2iys 


19 


13 


2 


19 


17 12-% 


14 


2m 


2514 


22 


15»4 


2 


21 


18M 12-1 




16 


343^ 


27M 


23^2 


18^2 


23/2 


23^2 


21M 16-1 



VERTICAL STANDARD TYPE 




Fig. 23-40. 



~~^ 



Sze 



Flanges 



r^ L Of No. & 

Drip iS"'' ?°, Size of 
Dmm. Circle Bo^g 



3 


IWs 


9% 


91^ 


Va 


7>^ 


6 


4-M 


4 


nVi 


n'A 


lOH 


% 


9 


7H 


8-% 


5 


20Ji 


13J/2 


11 J^ 




10 


sy?. 


8-M 


6 


24 


14»4 


12M 




11 


9y?. 


8-M 


8 


26M 


17^ 


17Ji 




13H 


itH 


8-M 


10 


321^ 


22 


23 




16 


UH 


12-K 


12 


33>^ 


25J4 


25 




19 


17 


12-% 


14 


41 


28}^ 


29?^ 


1/^ 


21 


18H 


12-1 


16 


48}i 


33?4 


31H 


1^2 


2314 


21M 


16- 1 



2a— 19 





Fig. 23-11. The Webster Grease and Oil Trap. 
Webster Grease and Oil Traps 

The Webster Grease Trap is for use in draining oil separators on exhaust 
steam hnes or on feed-water heaters, or for removing from the course of the 
steam any accumulations of oily drips at other points in the low-pressure 
steam mains or branches. It will operate with equal efficiency under any 
pressure from that of atmosphere to plus 15 pounds per square inch. It is 
not designed for use under high vacuum conditions. 

As shown in the accompanying sectional illustration (Figure 23-41) the 
valve mechanism is simple, and the discharge orifice is designed to give the 
full area of the inlet opening. 

The ball float and valve chamber are easily reached for quick cleaning 
without disturbing pipe connections. 

Properly installed, the Webster Grease Trap should be provided with a 
by-pass in the piping around it; a check valve should be in the line beyond 
the outlet and by-pass, and an equahzing or vent pipe should be run from 
the top of the trap to the exhaust main beyond the Oil Separator. 

Ratings for Webster Grease Traps: Because the mixture to be 
discharged is likely to be more or less viscous and sluggish in movement 
when it is cool it is impossible to rate Grease Traps on a condensation basis. 
The size of Grease Trap to be selected in any case is the same as the size of 
drip of the Oil Separator which it is to drain. 




,,%. », W Pipe Plug- ^ 

'A Pipe PluB -ifi ^"^ TT" 

1 




A' Size Outlet A=Size Inlet 

Hg. 23-12. 
23—20 



Table 23-S 


. ] 


dimensions of Webster Grease and 


Oil Traps 


Number 


A 


Ai 


B 


c 


D 


E 


F 


G 


H 


U 


V 


w 


0016 


H 


U 


13 


1 


7 


12=/^ 


4 


3 


25/^ 


75/8 


5H 


Vt 


016 


H 


Va 


VoVa 


1 


8 


15 


4i4 


3i/s 


2^8 


81/8 


6»4 


Va 


116 


I'd 


Wa 


191/s 


1^/8 


9 


18% 


5^8 


3^8 


4 


1054 


7 


1 


216 


2 


2 


20^8 


1^8 


10^2 


V^Vi 


Wi 


4^2 


4J/8 


VIVa 


8 


1^ 



All dimensions in inches and subject to slight variation. 



The Webster Vacuum Oil-Draining System with Tank and Alarm 

Where the Webster Oil Separator is installed in connection with a con- 
densing engine, a special method of separator drainage becomes necessary. 

An excellent arrangement for this purpose is shown, the apparatus con- 
sisting of a Standard Webster Horizontal Separator and a receiving tank 
of extra heavy wrought steel, made especially for and equipped with suitable 
fixtures for vacuum service. 



The drain from the oil separator is 
freely by gravity into the tank below it. 
from the tank to the steam line leading 
the pressure between the two. 

The whistle is attached to the high- 
is used for blowing down the tank. It 




Fig. 23-43. Vacuum Oil Separator Draining System 
with tank and automatic whistle alarm 



so connected that the drips fall 

An equalizing pipe is connected 

to the condenser, thus equalizing 

■pressure steam connection which 
is operated tlirough a series of 
levers, by a counter -balemced 
open sink pan (performing the 
functions of a float) placed 
within the tank. As soon as 
the drip accumulates to a 
point where the tank should be 
emptied, the pan rises and causes 
the whistle to give an alarm to 
the engineer, who closes the valve 
in the drain pipe from the separa- 
tor and the valve in the equal- 
izing pipe, and opens the steam- 
ing-out valve and the tank drain. 
The contents will then pass from 
the tank into the receptacle pro- 
vided for such oily drips, or to 
waste. 

The whistle alarm, together 
with the sink pan and regulating 
gear operating it and the gauge 
glass for the tank, are provided 
as standard fixtures with the 

: tank, but hand valves and con- 
necting piping shown are not 
furnished. 

Built in sizes from 8 to 24 
inches, inclusive, and in larger 
sizes upon special order. 



Webster Low-Pressure Receiver Oil Separators 

These separators, acting as eliminators of oil and condensation and as 
receivers or mufflers, are used chiefly in exhaust steam lines between recipro- 
cating engines and low or mixed-pressure turbines, or as receivers for the in- 
termittent exliaust from groups of steam hammers. 



23—21 



They are of riveted steel con- 
struction, with cast-iron nozzles, 
and, in common with all the 
Webster OU Separators, are equip- 
ped with hooked steel multi- 
baffles. 

The illustration shows one of 
the many forms of the Webster 
Low-pressure Receiver Oil Sepa- 
rator. The inlet and outlet noz- 
zles may be located to conform 
with any direction of flow of 
steam. The axis of the shell may 
be either horizontal or vertical. 




Fig. 23-44. The Webster Low-pressure Receiver Oil 
Separator. 



Inquu-ies regarding the Webster Low-pressure Receiver Oil Separators 
should be accompanied by a sketch showing the proposed location of and 
space available for the separator, the sizes and locations of inlet and outlet 
nozzles and the dkection of flow. The inquu-y should state the maximum 
amount of steam to be purified. 





Fig. 23-45. The Webster Suction Strainer. 



The Webster Suction Strainer 

The Webster Suction Strainer is used to exclude from the cylinder 
of the vacuum pump the dirt and scale brought down with the condensation 
from a vacuum heating system. The use of this strainer prevents scoring 
of the pump-cylinder lining, valves and piste n rods and the serious efiiciency 
losses and repair bills that would follow such scoring. The strainer is pro- 
vided with a tapping for the introduction of cold mate-up water when same 
is desired and when specially ordered a spray nozzle is provided to insure 
thorough mixture of cold water and vapor in return. Another tapping is 
provided for a connection to the vacuum gauge and a third plugged outlet 
is for draining the body when the strainer is not in use. The shell and re- 
movable cover are of cast iron with composition gasket in the joint. Com- 

23—22 



panion flanges, drilled low pressure standard, are provided for inlet and out- 
let connections. 

The basket is of perforated brass, and has at its top rim a casting in 
which is fastened a handle for hf ting out the strainer. The perforations are 
.043 inch in diameter and of sufficient number to provide a total area twice 
that of the entering pipe. 

The Webster Suction Strainer is to be placed in horizontal piping only, 
and should be set so that the axis of the body will be vertical. Water 
flows to it in the direction of the arrow (see exterior view), and its course 
through the strainer is evident from the sectional view on the previous page. 

During the cleaning process it is customary, if the system must be main- 
tained in operation, to use either the relay pump or the ejector, if there is 
one, and if not, to temporarily run the returns by gravity to the sewer or 
waste, closing the stop-valve in the main return. The entire operation oc- 
cupies but a few minutes. 

Table 23-10. Dimensions of Webster Suction Strainer 

K- No. and Size Bolts 

N Tapped and Plugged 

For maximum ''' — '— ^ 

working pressure 
of 15 pounds 





Fig. 33-46. 
All dimensions in inches cind subject to slight variations. Companion flanges furnished up to 12 inches. 



2 


5^ 


43^ 


12 


6 


eVs 


5M 


4M 


4-^x2 


y?. 


y^ 


3 


6H 


iVs 


13 M 


IV2 


^Vi 


5M 


6 


4-5^x2M 


V>. 


Ya 


4 


8A 


5il 


l6Vs 


9 


105^ 


iVs 


iVi 


8-J^x2M 


Vi 


Ya 


5 


9H 


(>Vs 


18^ 


10 


12^ 


m 


W2 


8-Mx2M 


y?. 


Ya 


6 


10 a 


^^ 


20K 


11 


13ii 


9^ 


9}i 


8-Mx2M 


Yi 


Ya 


7 


12^ 


9A 


25 


riVi 


19J4 


13 


lOM 


8-Mx3 


% 


1 


8 


141^ 


9H 


27M 


13V2 


21 


14M 


IIM 


8-^x3^ 


% 


1 


10 


nn 


liM 


32M 


16 


24 J^ 


16M 


14M 


12-Kx3}4 


Vi 


1 


12 


21 


123^ 


38 


19 


29 


20 


17 


12-3/8x3% 


% 


1 



Webster Dirt Strainers 

Webster Dirt Strainers are used in steam heating systems to prevent 
dirt from entering radiator traps or traps on drip points, mains or blast 
coils. They provide convenient receptacles for retention and accumulation 
of pipe chips, rust, dirt, etc., where impurities can do no harm and where 
^they are easily and quickly removed. 

The use of these strainers greatly lessens the amount of attention re- 
quired ta keep the system in thoroughly efficient operation and eliminates 
tlie incentive for neglect that is always to be expected with dirt pockets 
composed of pipe fittings, which cost nearly as much to make and are never 
as good. 

23—23 





Class B (Straightway) Class A (Offset) Class G (High pressure) 

Fig. 23-47. Webster Dirt Strainers. 

Three models are made : Class A with offset and Classes B and C with 
straightway pipe connections. All have cast-iron shell and cover, the 
latter made easily removable by means of a yoke and screw, in classes A 
and B and threads and hexogon top nut in Class C. 

The basket is made from sheet brass perforated with .043-inch diameter 
holes. The total free area through the basket is one and a half times the 
area of the entering pipe. The sides of the basket are reinforced with strips 
which are continued upward to form a bale handle. This handle not only 
serves to make the basket easily removable but acts as a spring against 
the cover to hold the basket in place. 

The range of types and sizes offers a selection for any service conditions. 



Dimensions in inches and subject to slight variations. 
CLASS A CLASS B 




Table 23-11. Dimensions of Webster 

Dirt Strainers, Classes A and B 

Class A.— Offset (Fig. 23-48) 



No. Size A B 


Bi 


B= 


c 


D 


E 


F 


G 


H 


018-A1 Hor ^33^ 
118-A,1 orlM4M 
218-Ali4or2 6 


2?4 


2K 
3M 


5^ 

eVs 

8ii 


2 
3 


2)s 
3 


6 

"A 
9A 


2M 

3^2 
43-4 


2J^ 
3M 





Class B.— Straight 


way 


Fig 


23-.50 






No. 


Size A 


B 


B' 


W- 


c 


E 


F 


G 


H 


018-B 
118-B 
218-B 


Hor M 
1 orlJi 
lHor2 


1% 


1^ 

2M 
2M 


W2 

4K 


5,^ 
8ii 


2K 
3 


6 

7-5- 

' 16 
0-3- 
^16 


2% 

W2 

4k 


4M 



Fig. 23-49. 
Blass C. — For working pressures up to 100 lb. per sq. in. (Fig. 23-49) 



Size A 


B 


B' 


B2 


D 


E 


E' 


F 


G 


H 


u 


8 

1 


3if 

4^ 
5^ 


Hi 

2^ 


2^ 
2M 
3^ 


2J^ 
2^ 
2>^ 


1^ 

2 






2,^ 
2A 
2,^ 


2tV 
3iV 


3tt 

3M 



23—24 



The Webster Vacuum-pump Governor. 

The vacumu pump of a vacuum heating sys- 
tem should be as nearly automatic in operation as 
possible. 

The Webster Vacuum-pump Governor auto- 
matically controls the admission of steam to the 
pump cylinder or cylinders in proportion to the 
degree of vacuum required. 

When only part of the heating load is "on," 
just enough steam is admitted into the pump to 
produce the degree 'of vacuum required. When 
the need is greater, the supply of steam is auto- 
matically increased. 

The Webster Vacuum-pump Governor can be 
adjusted to control the vacuum to any prede- 
termined degree, and may 
be readjusted when neces- 
SEU-y. 

It is remarkably sen- 
sitive through a wide 
range of adjustment. 





Fig. 23-52. Fig. 23-53. 

Table 23-12. Dimensions of Webster Vacuum-Pump Governors. 



Size A 


B 


B< 


D 


E 


F 


F' 


v°- 


G 


H 


V 


% 


2% 


IH 


5 


9^ 


7^ 


lOM 


10^ 


\^ 


2J^ 


231i 


1 


m 


IH 


5 


9ys 


VA 


lOM 


n 


2 


2J^ 


24}^ 


Wa. 


4 


IM 


5 


9Vs 


8 


lOM 


nVi 


2 


2% 


245^ 


IV2 


4M 


IH 


5 


r/s 


85% 


lOM 


iiM 


2A 


2% 


25Ji 


2 


5H 


IM 


5 


9% 


8K 


lOM 


12 


2A 


2ys 


26A 


2H 


6?^ 


1% 


5 


9ys 


im 


10J€ 


13J^ 


3M 


2H 


28J^ 


3 


^H 


IH 


5 


9% 


nVi 


l^Vi 


14M 


i'A 


2% 


29^ 


3J^ 


8 


I'A 


5 


9% 


iiH 


lOJi 


145^ 


4 


2% 


30 



23—25 




Fig. 23-34. 
W ebster Lift Fitting 



Webster Lift Fittings — Series 20 

Webster Lift Fittings are special devices used in 
pairs at points in Vacuum Heating Systems where con- 
densation is to be lifted to a higher level. The con- 
densation is lifted vertically to a higher level in 
"slugs" on the air-lift principle; the slugs being ob- 
tained by the use of a comparatively small diameter 
vertical return with its lower end submerged in the 
well below the level of the horizontal return which it 
drains. The lower Lift Fitting allows the condensa- 
tion to accumulate in the well which is formed in the 
fittings until it seals the vertical passage, thus causing 
a shglit reduction of the vacuum on the inlet side and 
forcing the water from the well through the vertical lift pipe to the higher 
level. The upper Lift Fitting allows the condensation to flow into the 
horizontal return without flowing back into the lifting line. 

Lifts of six feet or over shoidd be made in steps rather than all in one 
rise. The same idea apphes to "drag hfts" when the condensation is to be 
lifted through a long, upwardly incUned return pipe. 

Webster Lift Fittings are a big improvement upon and should be sub- 
stituted for the home-made fittings which in the past have had to be made 
from combinations of ordinary tees or crosses and plugs, because nothing 
better was obtainable. Each Webster Fitting is a single casting, neat in 
appearance and correctly proportioned for capacity of well and for the area 
ratio of inlet to outlet. The use of these fittings eliminates aU the guess- 
work and uncertainty aJDOut proper operation. They cost less than combi- 
nations of fittings when the labor cost 
as well as that of the fittings is con- 
sidered. 

Each fitting is provided with a 
clean-out plug for removing any accu- 





Flg. 23-35. 
Typical application a£ Webster lift Fittinga 

23—26 



Fig. 23-56. 
Long Screwed 
Lift Connection 



Fig. 23-57. 
Long Planged 
Lift Connection 



mulation of dirt or other foreig nmatter from the Uft pocket. The larger 
sizes are flanged and .finished and drilled to the low-pressure standard. 




Fig. ^-58 

Table 23-13. Dimensions of Webster Lift 

Fittings in Inches — Series 20 





1 

IM 

VA 

2 

2^ 

3 

4 

5 

6 

8 

10 
12 



Screwed 



Flanged 



A 


B 


c 


D 


E 


% 


y?, 


^% 


2V^ 


234 


1 


% 


iH 


3 


31/s 


IM 


1 


SH 


3i/« 


3?4 


VA 


1 


6tV 


4tV 


414 


2 


IK 


bVH 


4yR 


4yR 


2i/^ 


IV, 


sy 


5»/s 


5y« 


3 


2i4 


uy 


9 


9Vk 


4 


3 


17 Vr 


lO^R 


1114 


5 


•iy? 


19^4 


12 V, 


12^ 


6 


4 


2m 


13^8 


14t^ 


8 


W? 


25 i4 


16 '4 


17 


10 


6 


31 Vs 


20i/s 


2oys 


12 


7 


343/2 


22^ 


23i^ 



y2 

H 

1 
1 
1 
1 
1 
1 
1 
1 
1 



Close screwed Close flanged 

lilt connection lilt connection 

Fig. "3-59 

Table 23-14. Minimum Distance Between 

Centers 

J^-in. Screwed Fitting A = Zyin. 

1-in. " " A = sy in. 

IK-in- " " A = 4J/^ in. 

l}|-in. " " A = i% in. 

2-in. " " A = sy in. 

21^-in. " " A = 8 in. 



3-in. Flanged Fitting 

4-in. " 

5-in. " 

6-in. " 

8-in. 
lO-in. 
12-in. 



B = 10^ in. 
B = 13J5 in. 
B = 14,^ in. 
B = 15i| in. 
B = 18t^ in. 
B = 22V ' 



„ -.^2^ in. 
B = 2311 in- 



Webster Receiving Tanks, Plain Water-Control and Steam-Control Types 

These tanks are used in connection with vacuum steeun heating systems, 
to provide a place for storage of the condensation discharged by the vacuum 
pump and for liberation of the air that comes over with this condensation. 
Each type is designed for pressures not exceeding 15 pounds per square 
inch, for instaUation in horizontal position, and each type has proper re- 
ceiving capacity and air-hberating surface. 

The Plain Type receives the condensation and air tlirough an end 
opening near the top. The air escapes through a vent in the top of the tank, 
and the water flows by gravity to the bottom outlet and to the feed-water 
heater or other point of disposal. If the rate of flow of returns to tank ex- 
ceeds rate of discharge from tank, the excess overflows through an opening 
on the end near the top. 

The Water-control and Steam-control types have regulating valves 
which are operated by sink pan and rigging similar to those used to regulate 
the water level in Webster Feed-water Heaters. These two types are also 
provided with perforated sections or baffles, to insure best operation of the 
sink pan. 

The Water-control Type has its regulating valve arranged to autamatic- 
aUy admit "make up " at all times when the returns from the heating system 
are temporarily insufficient to keep the water level in the tank at the pre- 

23—27 





Fig. 23-69. Webster Air-Separating 

Tank and Receiver Steam-control 

Type. 



i;;. 23-61 Webster Air-separating 
Tanli nd Receiver, Water-control 
Type. 



determined point. The air is vented to atmosphere, the water flows by 
gravity to the heater or other place of disposal, and any excess of water 
overflows, as with the Plain Type. 

The Steam-control Type, which is used where the boiler or boilers are 
to be fed in proportion to the returns reaching the receiving tank, has its 
regulating valve installed in the steam supply line to the boiler-feed pump. 
With water in the tank at or above the predetermined level, the boiler-feed 
pump is in operation, feeding the returns into the boiler, but when the tank 
level is below normal, the steam to the boiler-feed pump is shut off and the 
pump stopped until sufficient returns coUect again. Make-up water, if 
necessary, may be introduced into the tank by hand. The venting of air 
to atmosphere, delivery of water by gravity flow and provision for overflow 
of excess water are the same as in the Plain Type. 

AU three types of Webster Receiving Tanks are made from riveted 
flange steel and have flat heads. The Water-control and Steam-control 
Types have removable manhole covers and gauge fittings in one end. Each 
tank is hand-made throughout from best obtainable materials. The sizes 
hstsd are standard. Larger sizes made only on special order. 



23—28 



Table 23-15. Dimensions of Webster Receiving Tanks 
Note: Openings will be bushed to suit requirements. All dimensions in inches. 



Plain 
Type 



Pig. 23.^2. 




Size 


Inlet 


Omiet 


Air Vent 


Overflow 


A 


B 


C 


18x48 
24x72 
36x96 


4 

5 

8 


4 

5 

8 


1% 

2 

3 


4 
5 
6 


25 J^ 
38M 
50K 


25 
37 
49 


3J4 

113^ 



->l Water Regulating Valve 



Water- 
control 
Type 



Kg. 23-63. 




^Outlet 10 Heater 









l< E >\ 














Size 


Inlet 


Outlet 


Air Vent Overflow Reg. Valve A 


B 


c 


D 


E 


F 


G 


18x48 

24x72 
36x96 


4 

5 

8 


4 
5 

8 


IM 4 1 25% 

2 5 IH 37^ 

3 6 2 50M 


30M 

42 J4 
54^ 


6 


12 
18 

18 


241^ 
36M 
48% 


14 
18 

24 


23 

28Ji 



Steam- 
control 
Type 



Fig. 23-64. 




^Outlet to Heater 









K E ^ 














Size 


Inlet 


Outlet 


Air Vent Overflow Gov. Valve A 


B 


c 


D 


E 


F 


G 


18x48 
24x72 
36x96 


4 

5 

8 


4 

5 

8 


IH 4 1 25J^ 

2 S Wi ZIH 

3 6 2 50M 


30H 

42^ 
545^ 


3^ 
6 


12 
18 

18 


24M 
36M 

48% 


14 
18 

24 


18Ji 
23 

28Ji 



For ratings see Table 14-00, page 00. 



23—29 





Fig. 23-65. The Webster Suction Strainer and Vapor Economizer. 
The Webster Suction Strainer and Vapor Economizer 

This special device, in addition to its function of protecting the vacuum 
pump, has a particular advantage in vacuum heating systems where some 
unusual operating condition results in the return of water to the vacuum 
pump at a high temperatm:e. 

Under such conditions, re-evaporation or transformation of water into 
steam vapor may occm, and the presence of this steam vapor adds to the 
duty of and may interfere with the proper operation of the pump. 

If cold water is constantly required for making up the boiler-feed water 
it can be introduced in the standard Webster Suction Strainer, by the use 
of the Webster jet-head, without increasing the cost of plant operation. 
The special Webster Suction Strainer and Vapor Economizer is designed 
to meet conditions where no make-up water is required, and where the use 
of such water would entail waste. 

The cold water is passed through a nest of copper coils and absorbs the 
heat of the steam vapor in the main return. 

This water is not handled by the vacuum pimip £uid does not mix with 
the condensation in the main return hne, as the Economizer becomes 
merely an extension of the hot water piping system, under the available 
pressure. 

23—30 



Table 23-16. Dimensions of the Webster Suction Strainer and Vapor 

Economizer 



Note:- 
All dimensions 
are in inches 
and subject to 
sliQht variations 




Hg. 23-66. 
All dimensions in inches and subject to slight variation. 



Size A 


B 


Bi 


c 


D 


D> 


E 


F 


G 


J K 


T3 


U 


M Est.Wt 


3 
5 

7 


19^ 
22M 
2SH 


6 

6M 

7M 


22 
25Y 


10 

123^ 

uy2 


15H 
2iK 


7^ 
10 
12}^ 


5}^ 

7K 


12 

19 


6 4-^x21^ 
8^ 8-Mx2M 
lOH 8-Mx3 


2M 
3}^ 

43/8 


65^ 
6934 
78 


1^ 600 lb. 
Yi 750 lb. 
M 900 lb. 




fe^Ttfe 




Fig. 23-67. Webster Combination (iauges. 
Gauges for Webster Systems 

Webster Gauges are of the same high quahty as all Webster apparatus 
and are furnished in various standard forms, and to suit special specifica- 
tions. 

The standard outfit furnished with Webster Vacuum Systems is a set 
23—31 



of two 53^-inch face, nickel- 
plated combination pressure and 
vacuum gauges, mounted on 
Monson, Me., slate board with 
Webster System name plate, 
thus identifying the system. 

Single combination gauges 
are also furnished, both for 
Vacuum and Modulation Sy- 
stems, in Si/o-inch size. 



/Connect to Low-pressure HoatinQ Main not teasrthan 15 
( distant from Pressurc-reaulating Valve 



3/4 X 3/4 X 1/4 Tee 



As deep as possible 
not iess tiian 4'0" 



WEBSTER 
RETURN TRAP 



Connect to 
Vacuum Reton 




From WEBSTER 
VACUUM GOVERNOR 



Single gauges are also fur- 
nished with Webster Hylo Vacu- 
um Sets, as elsewhere described. 
Larger gauges or slate or marble 
boEirds for three or four gauges 
can also be furnished when re- 
quired. 

Fig. 23-68. Connections for Gauges, Webster Vacuum System 
The Webster Modulation Vent Trap 




3/4 X 3/4 X 1/2 Tee 
3/4 Dirt Pocliet 
Cap 





Fig. 23-69. The Webster Modulation Vent Trap. 



This device is installed in 
the low point of the dry return 
line of the Webster Modulation 
System before the returns flow 
back into the boiler as feed 
water. It affords a simple, de- 
pendable method of venting the 
entrained air to atmosphere 
and of automatically insuring 
the return of the water to the 
boiler under fluctuating boiler 
pressures. The air vent is 
controlled by an internal float 
mechanism which is 
23—32 



1/4 Tap-Vent to Air 



1/+ Tap-Returns 
trom Heating System 




The above dimensions apply to all sizes of this type of Trap 

Fig. 23-70, Dimensions of Webster Modulation 
Vent Trap, Series 20. 

entirely free from mechanical troubles. 



Other means for returning water to the boiler are provided where 
structural features of the building or conditions of use are involved, but for 
the average building to which the Webster Modulation System is adaptable 
the Webster Modulation Vent Trap is used. 



Ceiling Line 



If Inlet Connection is 
not used Plug same 



WEBSTER MODULATION VENT TRAP- 



%" for * 120 VENT TRAP 
1" for a 220 VENT TRAP 
IX" for # 320 VENT TRAP 




Tfiis Distance must not be less than 
30" and as mucfi more as possible 
depending on Local Conditions 



Water Line of Boiler 



This Connection must be on same 
Centre as Wet Retur. ft ""^jble 



Special Swing 
Check Valve 



Connect into Wet Return Main 



Wet Return near Floor 



Fig. 23-71. Typical Installation of the Series 20 Web.ster Modulation Vent Trap. 
Webster Hylo Vacumn-Control Sets 

Each Webster Hylo Set consists of a Webster Hylo Vacuum Con 
troUer, handling vapor and air only, a Webster Hylo Trap, handhng water 
of condensation only, Webster Hylo Vacuum Gauges, and when needed, a 
Webster Lift Fitting. 

The Webster Hylo Vacuum Controller regulates the vacuum from the 
low to the high vacuum through the action of the diaphragm and pilot 
valve. The vacuum differential, as fixed by the position of the weights on 
the diaphragm lever, may be anything from the high vacuum to almost 
nothing, as needed. 

The Webster Hylo Trap permits condensation to flow from low to 
high vacuum without loss of differential. This trap is of ball-float type, with 
outlet water sealed. 

The Webster Vacuum Gauges indicate the vacuum conditions upon 
both sides of the controller. Specied arrangements of gauges and boards 
can be furnished where desired. 



23—33 



The Webster Lift Fitting operates on the "air-hft" principle, to assist 
in raising condensation back to level of the return pipe. 




Fig. 23-72 
Table 23-17. Dimensions of the 

Webster Hylo Controller 

AH dimensions in inches and subject to 

slight variations. 



Fig. 23-73 
Table 23-18. Dimensions of the Web- 
ster Hylo Trap for 15-Ib. working 

pressure. 
All dimensions in inches and subject to slight 

variation. 



Size A B 


c 


D 


F 


G 


H 


u 


1 


3H 


12^4 


11 1^ 


iH 


2% 


\Wa 


9H 


IH 41^ 


12S/4 


UK 


Wa 


2 'A 


i-O'H 


10 


2 .5 


12H 


UM 


2 


3 


i-m 


10^ 



Number 


A 


Ai 


B 


c 


D 


E 


F 


G 


H 


u 


V 


W 


0016 


Va 


H 


13 


1 


7 


\2% 


4 


3 


25^ 


71/^ 


5J^ 


^ 


016 


% 


■a 


15^4 


1 


U 


15 


4^s 


3i/« 


2'^« 


8^8 


6^ 


?i 


116 


IH 


Wa 


19i/s 


1^/s 


9 


l«^/s 


5»/s 


3% 


4i/8 


10^ 


7 


1 


216 


2 


2 


2W% 


1^8 


10^2 


19K 


6^8 


4H 


m 


12M 


8 


1^ 



The ratings are the same as for the Webster Heavy- 
duty Trap, as given in Table 00-00. 



The Webster Damper Regulator 

The Webster Damper Regulator 
is used with the Webster Modulation 
System and automatically controls the 
opening of the draft door and check 
damper of the low-pressure, steam- 
heating boiler. It is extremely sensi- 



Note:-To support Damper ReQulatoi 
use 4-y2"Rods with Pipe 
Separator and make lengtl 
to suit work, remove 
any 4 Bolts to suit 





34 'Connection to Live 
Steam Main 



HA" Drain Pluooed 



Fig. 23-74. 
23—34 



The Webster Damper Regulator. 



Fig. 23-75. 
Dimensions of the Webster Damper Regulator. 



Other means for returning water to the boiler are provided wher 
structural features of the building or conditions of use are involved, but fo 
the average building to which the Webster Modulation System is adaptabl 
the Webster Modulation Vent Trap is used. 



CeilinQ Line 



It Inlel Connection is 
not used Plug same 



WEBSTER MODULATION VENT TRAP- 



''/." lor # 120 VENT TRAP 
1 " for * 220 VENT TRAP 
VA" lor #320 VENT TRAP 




This Distance must not be less than 
30" and as much more as possible 
depending on Local Conditions 



Water Line of Boil 



This Connection must he on same 
Centre as Wet Retur. 1 .•' :^ le 




Connect into Wet Return Main 



Wet Return near Floor 



Fig. 23-71. Typical Installation of the Series 20 Webster Modulation Vent Trap. 
Webster Hylo Vacuum-Control Sets 

Each Webster Hylo Set consists of a Webster Hylo Vacuum Coi 
troller, handling vapor and air only, a Webster Hylo Trap, handhng wate 
of condensation only, Webster Hylo Vacuum Gauges, and Avhen needed, i 
Webster Lift Fitting. 

The Webster Hylo Vacuum Controller regulates the vacuum from th 
low to the high vacuum tlirough the action of the diaphragm and pilo 
valve. The vacuima differential, as fixed by the position of the weights oi 
the diaphragm lever, may be anything from the high vacmmi to almos 
nothing, as needed. 

The Webster Hylo Trap permits condensation to flow from low t( 
high vacuum without loss of differential. This trap is of baU-float type, wit) 
outlet water sealed. 

The Webster Vacuum Gauges indicate the vacuum conditions upoi 
both sides of the controller. Special arrangements of gauges and board; 
can be furnished where desired. 



23— .^3 



tive and accurate because of the ample diaphragm area and controls the fire 
to maintain the steam pressure always within a few ounces of that for which 
the regulator is set. 

Table 23-19 Power Developed by Webster Damper Regulator 

The following figures based upon tests with lever in mid-position afford a comparison with other 
Hamper regulators having much smaller diaphragms. 



Pressure in lb. per sq. in J^ 

Average pull at end of lever, lb 4.125 



1 
8.25 



2 
16.5 



3 

24.75 



4 
33 



S 

41.25 



Webster Conserving Valve 





Fig. 23-76. The Webster Sylphon Conserving Valve 

This valve is one of the modifications used in connection with the 
Web t?r Vacuum System when steam is furnished direct from low-pressure 
heating boilers, which £u-e required to supply steam for other purposes than 
waiming the building, at a constant pressiue above that required for the 
heating system alone. 

It also insures the constant operation of the low-pressure steam-driven 
vaci um pump. 

It is placed in the main steam line from boiler, the steam connection to 
vacuum pump being teiken from the inlet side of the conserving valve. The 
pressure for which the conserving valve is set must be built up on the inlet 
side, before the conserving valve will open and allow steam to enter the low- 
pressure heating main. 

In consequence, the vacuum pump will automatically start into oper- 
ation before steam is admitted into the low-presstire heating main. The 
partial vacuum created in the retiu-n mains and radiators assures quick 
circulation as soon as the conserving valve automatically opens and permits 
the steam to flow into the main. 

Inversely, when steam is cut off the heating system the pump wiU 
continue to operate until the condensation is thoroughly drained, assuring 
the return of all of the condensation to the boiler. With the type of boiler 
used with the heating systems of this design, this is a very important matter. 



23—35 




Fig. 23-77 

Table 23-20. Dimensions of Webster Conserving Valves 
All dimensions in inches and subject to slight variations 



Size A 


B 


c 


E 


F 


G 


J 


K 


R 


u 


4 


12 


20 


9 


9% 


Wi 


7J^ 


8-^ 


2M 


16f| 


5 


12 


20 


10 


9% 


5M 


8>^ 


8-M 


2M 


Hit 


6 


13 


nVi 


11 


lOM 


6:^ 


9^ 


8-M 


2M 


19A 


8 


13M 


31M 


13H 


liM 


1^ 


llM 


8-M 


2M 


21il 


10 


15 


36,% 


16 


i2y2 


w% 


MM 


12-% 


3a^ 


25 H 



The Webster Higb-Pressure Sylphon Trap 




Fig. 23-78. The Webster ffigh-Pressure Sylphon Trap 

This trap is in many respects hke the standard Webster Sylphon Trap 
described on page 00. The body construction is the same except that the 
position of inlet and outlet opening and the spud connection of the inlet 
are reversed. 

As the trap must operate at comparatively high steam pressure with 
resulting high temperature, the thermostatic member or bellows is located 
outboard of the valve. The sylphon bellows, sinrounded in this position 
with the cooler vapor from the discharged condensate, is extremely sensitive 
to the much higher temperature of the steam, and consequently acts quickly 
and positively to close the valve against steam passage through the trap. 

23—36 



I 



In consequence also of the higher pressure, the valve piece and the seat 
are constructed of monel metal, which successfully resists wire-drawing and 
its accompanying wear. 

The Webster High-pressure Sylphon Trap is made in three sizes and 
for two pressure ranges — Class 2 for pressures up to 50 pounds per square 
inch, and Class 3 for pressures to 100 pounds per square, inch. . 

Apphcation diagrams for this device are shown on page 00 of Chapter 19. 

Table 23-21 Dimensions of Webster High- 
pressure Sylphon Traps 




SIZE 


A 


B 


C 


D 


J^"— 822 

% —833 

1 —844 


334" 
4A 


W2 


3M" 
2M 

3M 


2M" 
4H 



Fig. 23-79 
The Webster Low-pressure Boiler Feeder — Series 14 

In connection with heating boilers fed from hydro-pneumatic tanks, and 
under certa n other conditions, a Webster Boiler Feeder is necessary. This 
device is shown in the diagram on page 00, as part of a Webster Hydro- 
pneumatic System. 



I 




WATER INLET 



EQUALIZING PIPE 




FEEDLINEl': TO BOILER'^ 



EQUALIZING 
PIPE 



Fig. 23-81. Conventional 
arrangement of Webster 
Low-pressure Boiler Feeder 



Fig. 23.80. Webster Low-pressure Boiler Feeder 

When the water level in the boiler 
lowers, the ball float opens the feed 
valve and allows the water to discharge 
d rectly to boiler. 

The valve is of the double-balanced 
type with large orifice area, because of 
the low d fferential between the tank 
pre sure and the boiler pressure. The 
ball float is large enough to give the power required to move the valve 
lever without excessive difference of water level. 

An important point in the construction of the boiler feeder is that the 
valve and gea^- are within the casing. There are no outside glands to keep 
t o^ht and any leakage wliich occurs is within the body of the device and 
hence into the boiler. 



H SUPPORT FOR FEEDER 



The working parts are easily accessible, but seldom need attention. 



23—37 




Fig. 23-82 
Table 23-22. Dimensions of Series 14 Webster Low-pressure Boiler Feeder 

Dimensions in inches and subject to slight variation 



Number A 


Ai 


B 


Bi 


c 


E 


F 


G 


G' 


H 


N 


u 


Estimated 
Weight 


114 


M 
1 


1 

1 
1 

1 


12^ 

12J^ 

12 J^ 


2 
2 

2 
2M 


25?^ 
253/i 
25 J^ 
255^ 


14^ 

14^ 
14^ 
14}^ 


6M , 


IM 

IK 
IK 
IK 


2 


11'/^ 

11^ 
11?^ 


10 
10 
10 
10 


15^ 
15^ 
15=^ 
15^ 


217 
220 

222 
225 


214{ 


2 


2 

2 


15 
15 


2M 
2M 


31^ 
31^ 


16!^ 
16J^ 


7M 


2M 
2M 


2Va 
2% 




12 
12 


19 Ji 
19 J^ 


305 
310 


314{ 


3 


2H 
2^ 


19 
19 


3M 
3^ 


36M 
36M 


18}^ 
18J^ 


8 
8 


3 
3 


3 

3M 


15 
15 


12 
12 


20K 
20K 


450 
460 



Webster Hydro-Pneumatic Tanks 

Single and Double-control Types 

Webster Hydro-pneumatic Tanks are used in place of open-vent tanks 
for receiving returns in steeun heating systems where sufficient head room to 
produce the necessary static head is not available for the installation of a 
plain receiving tank. 

The general design is the same as that of Webster Steam-control and 
Webster Water-control Receiving Tanks, except that in the Single-control 
Hydro-pneumatic Tanks the sink pan and rigging control the escape of 
air through the vent pipe and in the Double-control type this feature is 
supplemented by an additional sink pan rigged to control a water valve in 
the tank discharge. 

In both Single and Double-control types the air is permitted to escape 
freely until the tank is half filled with condensation, when the vent closes 
and the remaining air is confined. The air vent is open whenever the con- 
densation flows by gravity against the resistance in the outlet connection. 
When the necessary head is greater than that due to the tank being half 
fuU of condensation, the air vent is closed. Further accumulation of air 
and water creates additional pressure until this added to the gravity head 
overcomes the resistance and condensation flows through outlet until water 
line reaches middle of tank. Then the air vent opens to permit escape of 

23—38 




Fig. 23-83. Webster Hydro-pneumatic Tank, with Double Control. 

air. When the tank has no gravity head to the heater or boiler the necessary 
head to overcome the resistance in the outlet is by confined pressure only. 

The Double-control Hydro-pneumatic Tank in addition has its water- 
control valve arranged to close just before the water level reaches the bottom 
of the tank. The Double-control type serves to prevent the admission of 
air into the system through the discharge from the tank when the pressure 
in the open feed-water heater or boiler may be less than that of the atmos- 
phere. 

Both Single and Double-control Tanks are used under pressure greater 
than the atmosphere and must be provided with means for preventing ex- 
cessive pressure due to obstruction of overflow. For this purpose a water- 
r ilef valve is provided, which should be piped to an open funnel to facihtate 
ob ervation and correction of unnecessary waste. 

Both Single and Double-control types of tanks are made of riveted 
flange steel plate, have flat heads and are for installation in horizontal 
position. A perforated inside baffle running along the top serves to dis- 
tribute the water and this makes certain that the sink pans are kept filled 
with water. 

Manholes and covers and gauge glass fittings are regular equipment 
with both types of tanks. 

The sizes listed are standard, but others can be made to order. 



23—39 



Table 23-00. Dimensions of Webster Hydro-pneumatic Tanks 
Openings will be bushed to suit requirements. All dimensions in inches. 
Single-control Type. 




Fig. 23-84. 



Size 


Inlet 


Outlet 


Vent Valve 


Overflow 


A 


B 


c 


D 


E 


F 


G 


18 


x48 


4 


4 


¥4. 


4 


26M 


303^ 


3H 


12 


24^ 


14 


18 


24 


x72 


5 


5 


IM 


5 


384 


42^ 


6 


18 


36M 


18 


22M 


36 


x96 


(2)8 


8 


W2 


6 


50J^ 


545^ 


IIJ^ 


18 


483^ 


24 


28M 



Double-control Type. 

-B- 




Fig. 23-85. 



Size 


Inlet 


Outlet 


Vent Valve 


Overflow A 


B 


C 


D 


E 


F 


G 


H 


J 


18 X 


48 


4 


4 


% 


4 


29M 


30}4 


10 


12 


241^ 


14 


18 


20 


1914 


24 X 


72 


5 


5 


IJ^ 


5 


43M 


421^ 


13 


18 


36M 


18 


22M 


22 


2534 


36 X 


96 


(2)8 


8 


m 


6 


58 


54J^ 


18 


18 


48J^ 


24 


28M 


313g 


35 



For ratings, see Table 14-00, page 00. 



23—40 



Webster Expansion Joints 

Webster Expansion Joints are constructed with cast-iron bodies and 
brass-slip sleeves and in both single and double shp types. The single 
types may be specially equipped with ball-and-socket joints, which are of 
value for preserving the proper alignment of the steam piping. 

The body of the Webster Expansion Joint is provided with anchors 
made integral with the body castings for rigid connection to a foundation or a 
bracket. Service connections 6ire provided for greatest convenience in 
tapping the steam main for branch piping. 



Fig. 23-86. Class D (at left). 
Webster Expansion Joint. 



» 




Fig. 23-87. Class DH (at right) 
Webster Expansion Joint. 




Fig. 23-88. Class G (at left). 
Webster Expansion Joint. 



Fig. 23-89. Class GH (at right). 
Webster Expansion Joint. 




23—41 



.^n 



M-StzeoFServfcft 
ConnecHon.- 




l/VDrJp. 
SIZES 

7* ho 20' Inclusive. 



Fig. 23-90. 



Table 23-24. Class D Webster Expansion Joints for Low-Pressure Steam 

Maximum working pressm^e, 15 lb. per sq. in. 

This joint has single shp and maximum traverse of 5 inches and is made 
with a close-grained cast-iron body and brass tubing or cast sleeve. 

Standard equipment includes service connections, anchor plates and 
gland packing. Companion flanges are furnished only when specially 
ordered. Flanges are drilled low-pressure standard unless specially ordered 
otherwise. 

Dimensions (in inches) 



Size 


B 


B' 


c 


D 


D' 


E 


F 


Fi 


G 


J^ 


P 


Ki 


M 


2 


6 


VA 


13J4 


3 


3 


6 


2J^ 


3 


2J^ 


Wx 


m 


2- ^ 


ll/( 


21^ 


6H 


41/8 


14J^ 


3 


3 


7 


314 


^Vi 


3M 


m 


Wx 


2- M 


2 


3 


6^ 


41/s 


14M 


3 


3 


iy2 


2% 


^V% 


2Vi 


1% 


m 


2- M 


2 


314 


7H 


41/^ 


16 


4 


4 


zVi 


3^ 


SH 


3^ 


2 


2 


4- K 


2 


4 


71^ 


4^/^ 


16 


5 


5 


9 


4 


m 


4 


2'/« 


21/. 


4- % 


2V, 


5 


SVs 


^Yh 


171^ 


5 


5 


10 


4}^ 


5J^ 


41^ 


21/2 


2y?. 


^ Vs 


2^ 


6 


Wi 


Wh 


17M 


6 


6 


11 


5 


5Ji 


5 


3 


3 


4- v^ 


21/5 


7 


12^ 


7 


20 J^ 


6 


6 


12J^ 


6^ 


6H 


5^ 


3 


3 


4^ J^ 


3 


8 


13^ 


ly?. 


2VA 


6 


8 


13Ji 


714 


7J4 


6 


5 


3 


4^ >i 


31^ 


10 


14^ 


TH 


zsVi 


6 


8 


16 


8^ 


8V2 


7 


5 


3 


4-1 


4 


12 


15 >^ 


8% 


25 J^ 


7 


8 


19 


9M 


9% 


8J^ 


5 


3^ 


4-1 


5 


14 


17^ 


Wx 


281^ 


8 


8 


21 


lOM 


10^ 


8M 


5 


4 


4-1 J^ 


6 


16 


17M 


9% 


28^ 


8 


8 


231^ 


12 


11>^ 


10 


5 


4 


4-11^ 


6 


18 


18 


9V4 


28% 


8 


12 


25 


13M 


131^ 


11 


9 


4 


tr-lVs 


6 


20 


18 


9H 


30^ 


8 


12 


27 J^ 


14M 


14^8 


12 


9 


4 


4r-lH 


6 


23^2 



























^pnaiiDSia: 



f*5izeof Servica 

/ Connect ioiLi- 



C-Closed- 



l'/*Drip i 



/j "'y_. 




"•l/*Drip, 



Fig. 23-91. 



Table 23. Class DH Webster Expansion Joints for High-Pressure Steam 

Maximum working pressm-e, 125 lb. per sq. in. 

This joint has single slip and maximum traverse of 5 inches and is made 
with a close-grained cast-iron body and brass tubing or cast sleeve. 

Standard equipment includes service connections, anchor plates, Kmit 
bolts and gland packing. Companion flanges are furnished only when 
specially ordered. Flanges are drilled low-pressure standard unless specially 
ordered otherwise. 



Dimensions (in inches) 



Size 


B 


B' 


c 


D 


D' 


E 


E-' 


F 


Fi 


r- 


p 


K' 


M 


9 


6 


W^ 


13M 


3 


3 


6 


BH 


2K 


3 


m 


IM 


2- M 


IK 


2H 


6^ 


41/8 


143^ 


3 


3 


7 


lOH 


3M 


33^ 


VVa 


1% 


2-M 


2 


3 


6^ 


41^ 


UVz 


3 


3 


7H 


11 


2% 


3K 


IH 


m 


2- M 


2 


3^ 


IV2 


41/, 


16 


4 


4 


8J^ 


13 


3>^ 


3 3^ 


2 


2 


4- J^ 


2 


4 


tVi 


41^ 


16 


5 


5 


9 


12 


4 


4M 


zy?. 


2'/^ 


4- K 


2i^ 


5 


83-^ 


45^ 


17^ 


5 


5 


10 


141^ 


4>^ 


5J^ 


2^ 


2^ 


4- Vs 


2y. 


6 


8M 


47^ 


171^ 


6 


6 


11 


15H 


5 


5Vs 


3 


3 


4- K 


W9. 


7 


VH 


7 


20K 


6 


6 


12}^ 


17H 


6^ 


eVi 


3 


3 


4- 3^ 


3 


8 


IW2 


ly?. 


221^ 


6 


8 


13K 


18}^ 


7M 


^Va 


5 


3 


4r- Ji 


3i^^ 


10 


14^ 


r% 


233^ 


6 


8 


16 


21 M 


8^ 


S'A 


5 


3 


4^1 


4 


12 


153^ 


m 


25% 


7 


8 


19 


24M 


9M 


9H 


5 


•iy2 


4r-l 


5 



23^13 



Closed 




Fig. 23-00. 



Table 23-26. Class G Webster Expansion Joints for Low-Pressure Steam 

Maximum working pressm^e, 15 lb. per sq. in. 

This joint has double sUp and maximum traverse of 10 inches and is 
n>a e with a close-grained cast-iron body and brass tubing or cast sleeve. 

Standard equipment includes service connections, anchor plates and 
g a:.d packing. Companion flanges are furnished only when specially 
o ered. Flanges are drilled low-pressure standard unless ordered otherwise. 



Dimensions (in inches) 



Size 


B 


c 


D 


Di 


E 


F 


Fi 


J- 


P 


Ki 


M 


2 


nVa 


221^ 


3 


3 


6 


2J^. 


3 


IH 


IM 


2- M 


1^4 


2!^ 


nVs 


231.C ' 


3 


3 


7 


3M 


3J^ 


IH 


IM 


2-M 


2 


3 


12^ 


25M 


3 


3 


7J^ 


2^ 


3}^ 


IM 


IH 


2- M 


2 


31/, 


12^ 


25}-^ 


4 


4 


8y2 


3M 


3M 


2 


2 


4- % 


2 


4 


l^Vs 


26M 


5 


5 


9 


3J^ 


4ii 


2J^ 


2^ 


4- K 


21/, 


5 


13M 


?.7H 


5 


5 


10 


iVz 


SVs 


2>i 


23^ 


4- K 


2h; 


6 


13 >^ 


27H 


6 


6 


11 


5 


^Vs 


3 


3 


4- K 


21/^ 


7 


uvs 


28>^ 


6 


. 6 


12}^ 


6Ji 


W2 


3 


3 


4- J^ 


3 


8 


l5Vs 


31 M 


6 


8 


13J^ 


6J€ 


m 


5 


3 


4- Vs 


sy?. 


10 


17 


33K 


6 


8 


16 


8 


&V2 


5 


3 


4-1 


4 


12 


18^8 


36M 


7 


8 


19 


9 


9H 


5 


3J^ 


4^1 


5 


14 


ISVs 


37M 


8 


8 


21 


lOJ^ 


10^ 


5 


4 


4-1 >^ 


6 


16 


W/2 


38 J^ 


8 


8 


23J^ 


12 


11>^ 


5 


4 


4-1 J^ 


6 


18 


2oys 


40M 


8 


12 


25 


13M 


13^ 


9 


4 


4r-iys 


6 


20 


22 


44 


8 


12 


27^ 


14 


141^ 


9 


4 


4-11^ 


6 



23—44. 



B' 




.Closed 



Fig. 23-93. 



Table 23-27 Class GH Webster Expansion Joints for High-Pressure Steam 

Maximum working pressure, 125 lb. per sq. in. 

This joint has double slip and maximum traverse of 10 inches and is 
made with a close-grained cast-iron body and brass tubing or cast sleeve. 

Standard equipment includes service connections, anchor plates, limit 
bolts, and gland packing. Companion flanges are fiuriished only when 
specially ordered. Flanges eire drilled low-pressure standard unless specially 
ordered otherwise. 



Dimensions (in inches) 



Size 


B 


B 


c 


D 


D' 


E 


El 


F 


Fi 


r- 


J^ 


Ki 


M 


2 


161^ 


^Vs 


221/s 


3 


3 


6 


m 


23^ 


3 


Wa. 


m 


2- M 


114 


2H 


16J4 


8M 


23M 


3 


3 


7 


ioy2 


3K 


334 


1% 


IVa 


2- Vi 


2 


3 


ISVz 


9M 


25M 


3 


3 


7y2 


11 


2 '^8 


•iy?. 


1% 


1% 


2- M 


2 


3^ 


18 


9 


253^ 


4 


4 


9 


13 


334 


■6% 


2 


2 


4- Ji 


2 


4 


19 


9y2 


26M 


5 


5 


9 


12 


3V?. 


414 


23^ 


m. 


4- 3^ 


23^ 


5 


i9y2 


9H 


27 Vz 


5 


5 


10 


141^ 


41^ 


51/s 


2H 


2y>. 


4- 3^ 


2'^ 


6 


19M 


9J^ 


27M 


6 


6 


11 


15M 


5 


SV^ 


3 


3 


4- % 


2'^ 


8 


23 


IIJ^ 


31M 


6 


8 


133^ 


183^ 


6^4 


ly 


5 


3 


4- Ji 


33^ 


10 


24M 


1214 


337^ 


6 


8 


16 


21 M 


8 


^y?. 


5 


3 


4^1 


4 


12 


25 M 


i2ys 


36M 


7 


8 


19 


24M 


9 


9ys 


5 


3>^ 


4-1 


5 



-/.c; 



Table 23-28. Distance Between Anchor Points and Webster Expansion Joints 
for Various Steam Pressvure Conditions 

The following table is recommended as a guide in the design of stccim 
piping for determination of the proper points of installation of Webster 
lixpansion Joints. In such design the maximum pressure which the pipe 
hne must sustain during acceptance tests or other special conditions must be 
selected as the "Gauge Pressure." 



_ . _ . Safe Maximum Distance in 

Gauge Temperature Expansion Feet Between Anchors 

Pressure Difference I°,<lSf| . for Single-sUp 

Above Zero Per 100 Feet Expansion Joints* 






212 


1.53 


260 


5.3 


227 


1.64 


245 


10.3 


240 


1.73 


225 


15.3 


250 


1.8 


220 


20.8 


259 


1.87 


215 


25.3 


267 


1.93 


210 


30.3 


274 


1.98 


202 


40.3 


286 


2.06 


195 


50.3 


297 


2.14 


190 


75.3 


320 


2.31 


175 


100.3 


337 


2.43 


166 


125.3 


352 


2.54 


160 



*For Double-slip Joints, the safe distance from the joint to an anchor in each direction may be the distance 
specified for a Single Joint, provided the body of the Double Joint itself is securely anchored. 



23—46 



Webster Steam Separators 

Webster Steam Separators of the standard types for removing moistm^e 
from live steam, have cast-iron corrugated baffles against wiiich the steam 
impinges, causing a sudden change in direction of flow and consequently 
freeing the steam of the entrained moisture. 

The port openings in every Webster Steam Separator are of such size 
as to minimize loss of steam pressure from unnecessary friction. 

These separators may also be used for special purposes, as removing 
moisture from compressed air, assuring operation of steam whistles by re- 
moving moisture from their steam supphes. etc. 

The material ordinarily used in the sheUs is close-grained cast iron, 
but special shells of semi-steel, cast steel or other material can be furnished 
at extra cost. 



Webster Standard Steam Separators 







^^_^ 





Fig. 23-94. Class B. Vertical. 

For raa.ximum working pressure 

of 150 pounds per square inch. 

Sizes — 2 to 12-inch. 



Fig. 23-95. Class BH. Vertical. 

For maximum working pressure 

of 200 pounds per square inch. 

Sizes — 2 to 12-inch. 



Fig. 23-96. Class C. Horizontal. 

For maximum working pressure 

of 150 pounds per square inch. 

Sizes — 2 to 12-inch. 




Table 23-29. Dimensions of Webster 
Standard Steam Separators 

All dimensions in inches. 
Weights are approximate and 
do not include companion flan- 
ges, which are furnished only as 
extras and at extra cost. 




Fig. 23-97. Class B. 



Fig. 23-98. Class BH. 





CLASS B 






CLASS BH 






Flanges 




Size 


B 


H 


Drip 


Size 


B 


H 


Drip 


Out. 
Diam. 


Bolt 
Circle 


No. & Size 
of Bolts 


2 


21 


10^ 


y2 


2 


161^ 


lOM 


^ 


6y2 


5 


4- % 


3 


243^ 


12M 


H 


3 


19^ 


13 


M 


m 


6^ 


8- H 


4 


28 


15 


1 


4 


23}^ 


15^ 


1 


10 


^Vs 


8- M 


5 


3V4 


17^ 


1 


5 


25 


181^ 


1 


11 


9M 


8- M 


6 


35 


20 


1 


6 


28 


205^ 


1 


123^ 


UVa 


12- % 


7 


42 


201^ 


1 


7 


33 


20M 


1 


14 


nVs 


12- Vs 


8 


43 


23 


iM 


8 


35 


23=;^ 


IH 


15 


13 


12- % 


10 


51 


27^ 


IM 


10 


41 J^ 


27^ 


\Va 


nn 


15M 


16-1 


12 


60 


33^ 


IH 


12 


50M 


33 J^ 


IH 


2oy2 


im 


l^l^i 




Fig. 23-99. Class C. 







DIMENSIONS 








FLANGES 
















Out. 


Bolt 


No. & Size 


Size 


B 


F 


G 


H 


Drip 


Diam. 


Circle 


of Bolts 


2 


93^ 


4 


12^ 


7J^ 


V2 


6}^ 


5 


Ar-ys 


3 


IVA 


5% 


14J4 


lOJ^ 


M 


8M 


65^ 


8- M 


4 


13 J^ 


^Va 


16 


IIM 


1 


10 


7K 


8- M 


5 


UVs 


IVs 


17M 


14M 


1 


11 


9M 


8- M 


6 


16^ 


8J^ 


19>^ 


15M 


1 


12}^ 


lOJ^ 


12- % 


8 


201^ 


10^ 


2314 


2034 


1 


15 


13 


12- ys 


10 


24?^ 


12J^ 


263^ 


24}^ 


13€ 


\-'Va 


15M 


16-1 


12 


27K 


14M 


30 


29 


IJi 


2oy2 


17M 


16-1}^ 



23-^8 



Table 23-29. Dimensions of Webster Standard Steam Separators (Continued) 



All dimensions in inches. Weights eire approximate and do not include 
companion flanges, which gire furnished only as extras and at extra cost. 





Fig. 23-100. Class F and FH Horizontal Types. 
Maximum working pressure, Class F, 150 pounds, 
and Class FH, 200 pounds per square inch. Sizes, 
2 to 12-inch. 





Fig. 23-101. Class F and FH 



I 







DIMENSIONS 








FLANGES 








CLASSES F AND FH 






Out. 


Bolt 


No. & Size 


Size 


B 


H 


F 


G 


Drip 


Diam. 


Circle 


of Bolts 


2 


SH 


7H 


m 


l9Vs 


M 


6V2 


5 


4- % 


3 


9M 


10 


5^8 


2\Vs 


Vi 


8M 


6^ 


8- % 


4 


lOVz 


IIH 


^Vs 


23 


1 


10 


VA 


8- M 


5 


u% 


14 


iVs 


26 


1 


11 


9yi 


8- M 


6 


13 


15H 


1% 


28 Ji 


1 


12}^ 


10^ 


12- % 


8 


liM 


20 


lOJ^ 


32 


IM 


15 


13 


12- >^ 


10 


\m 


24M 


12M 


433^ 


IM 


17M 


15M 


16-1 


12 


2oy2 


29 


14M 


46 


IJi 


20}^ 


17M 


16-lJ^ 



\ 



Table 23-30 
Advantages 
of Using 
Steam 
Separators 



Protection 



Economy 



From 
Water 
Scale 
Grit 



In 
Operation 



In 
Installation 



Due io 

Priming 

Foaming 

Bends 

Pockets 

Radiation 



In 
Boilers 



In 
Piping 



Because of 
Less Lubrication 
Lower Water Rate 
Less Wear and Tear 

Because of 

Smaller Pipe Sizes Required 



For 

Engines 

Turbines 

Pumps 

Air Compressors 



23—49 



Special Types of Webster Steam Separators 
Working pressures up to 150 pounds per square inch. 








Fig. 23-102. 

Class L— Angle Type 

With Horizontal Outlet. 



Fig. 23-103. 
Class M— Angle Type. 
With Bottom Outlet. 




Fig. 23-104. 

Class N— Angle Type. 

With Top Outlet. 



Table 23-31. Ratings of Webster Steam Separators 
Pounds per minute at average gauge pressures. Based upon a pipe velocity of 6000 feet per minute. 



Size 



100 Lb. 

per 
Sq. Inch 



GAUGE PRESSURES 

125 Lb. 

per 
Sq. Inch 



per 
Sq. Inch 



200 Lb. 

per 
Sq. Inch 



10 
12 



35. 


43.3 


51.6 


66.6 


78.3 


96.7 


112. 


141. 


140. 


167. 


196. 


250. 


215. 


258. 


300. 


391. 


317. 


383. 


450. 


583. 


433. 


516. 


600. 


783. 


550. 


660. 


800. 


1000. 


883, 


1083. 


1250. 


1580. 


1250. 


1533. 


1800. 


2333. 



23—50' 



CHAPTER XXIV 
Specifications for Webster Systems 

THE following specifications cover typical Webster Systems only in a 
general way, and are subject to many variations. It is advised that 
wherever practical a Webster Heating Engineer be called into con- 
sultation during the preparation of plans and specifications for Webster 
Systems. 

Specifications for the Webster Vacuum System of Steam Heating 

(This specification is drawn for a system of the usual up-feed type. 
For the variations known as the Webster Conserving System and the Webster 
Hylo System, revised special clauses will be furnished by Weuren Webster 
& Company on application.) 

General: (Here specify the general requirements of the contract, such as intent of 
drawings and specifications; verification of measurements; co-operation with other con- 
tractors; foreman; ordinances; permits; protection of work and buildings ; rights reserved; 
extra work; return of specifications and drawings; payments, etc.) 

Cutting of Floors and Walls : The [building] [heating] contractor will cut all holes 
in floors and walls and provide trenches for piping which may be necessary for this work, 
and at completion make all repairs to floors and walls so cut. 

Scope of Work : This specification is intended to cover a 2-pipe low-pressure heating 
system known as the Webster Vacuum System of Steam Heating. 

It is intended to supply radiation for heating the building to a temperature of .... 
degrees fahr. when the outside temperature is zero or a corresponding equivalent difference 
in temperature, with doors and windows reasonably tight. 

Special Apparatus: The contractor is to secure from Warren Webster & Company 
the specified Webster Vacuum System Apparatus, which he is to erect and connect as part 
of this contract. 

Standard Apparatus: In addition to the special apparatus, this contractor is to fur- 
nish all other material and labor necessary for the complete work as shown on plans or called 
for in specifications. 

Radiation: All pipe coils must be made up of standard weight mild-steel pipe and 

best gray-cast iron fittings and manifolds. All radiators must be of the 

pattern equal in every respect to that manufactured by and must be of the 

heights and columns shown on plans. They must be of the [steam] [hot-water] type. 

{Note: If of hot-water pattern, specify that the radiators "shall be connected with the 
supply at the top and the return at the diagonally opposite lower comer." If of steam 
type, specify that they "shall be provided with eccentric bushings and connected so that 
the bottom of the return connection will be lower than the bottom of the supply connection." 
Where Webster Modulation Valves are to be used, hot-water type radiators should be 
specified.) 

Contractors supplying new radiation ordered for this work shall, if they be called upon 
to do so, demonstrate to the satisfaction of the owners or their authorized representative, 
that the radiation furnished contains in each section of the difl'erent types supplied the 
amount of prime heating surface mentioned in the Usts pubUshed by the manufacturers of 
the respective types. This must be demonstrated by actual measurement and the develop- 
ment of the exposed surface of the sections. 

The heating contractor is to instruct the manufacturer of the radiation that he requires 
same to be thoroughly pickled and cleaned before shipment and that the outlets are to be 
plugged with loose wooden plugs. The manufacturer must issue his certificate to the con- 
tractor showing that these radiators have been so cleaned. These radiators are to be kept 
plugged until same are connected up to the difl'erent pipe Unes. 

Air-valve tappings are to be omitted and the outlets plugged. 

Radiators must be tapped or bushed for sizes of suppUes and returns as shown on plans. 

24—1 



Coil Hangers: Overhead radiators are to be hung in special pipe hangers and in no 
case shall these coil hangers be more than 10 feet apart. 

Wall coils are to be hung on cast or wrought-iron plates spaced as directed by their 
manufacturer, screwed to IJ^-inch strap-iron brackets bent to shape, and securely fastened 
to the walls with 2 expansion bolts each. Brackets must be spaced not over 10-foot centers. 
Wall radiators must be hung as directed by manufacturers. 

Straps shall be painted 2 coats of lead and oil paint of colors as directed by owners 
before radiators are set in place. Owners must be given opportunity to paint walls or ceil- 
ings before radiators are set. 

Return Traps: The return end of every radiator, pipe coil or other form of heating 
unit must be provided with a Webster Return Trap (of the type selected). The size of the 
trap shall be governed by the amount of condensation from the radiation unit as called for 
on plans. The connections of Webster Return Traps must be made to the approval of 
Warren Webster & Company, who will provide the contractor with service details showing 
approved forms of connection. 

Supply Valves {Alternate for Webster Modulation Valves): Each radiation unit must 
be provided with a Webster Modulation Valve connected to the top supply tapping. 

{Alternate for Ordinary Supply Valves): Each radiation unit must be provided with a 
gate or angle pattern valve equal in every respect to that manufactured by 

The sizes of supply valves, the radiator tappings and the sizes of horizontal branches 
from risers to radiators must be as shown on the plans, or as hereafter described in this 
specification. 

Pipe: All low-pressure pipe must be standard full-weight, mild-steel equal to that 

manufactured by All high-pressure piping must be extra heavy. All screwed 

piping must be fitted with occasional flanged unions. 

Straighten all pipe, ream all burrs and remove all dirt before erecting pipe or fittings. 
Have all runs plumb and parallel with building. Provide Webster Expansion Joints of the 
types and sizes and at the points shown on plans. Support all pipes securely and in such 
manner as to permit imobstructed movement between anchorages for expansion and 
contraction. 

So far as possible, all horizontal runs must be graded in the direction of steam flow. 

Fittings: All fittings shall be best gray iron, straight and true and free from blow- 
holes or other defects ; equal to those manufactured by Fittings for low pres- 
sure shall be standard weight; those for high pressure shall be extra heavy. 

Valves: All check, gate and globe valves must be equal to those manufactured by 



Heat Mains: From the low-pressure side of pressure-reducing valve run a pipe to 
connect into the exhaust steam main where shown on plans. (Here should follow a descrip- 
tion of the course of the steam main and its branches.) 

Horizontal runs must grade not less than 1 inch in 25 feet. 

Live Steam Connection: Connect a . . inch line from outlet in live steam main 
(where indicated on plans) to the heating main through the pressure-regulating valve. 

This valve shall be . . inch size and equal to that manufactured by , and 

shall be set to reduce the steam pressure from ... to (1 lb. per sq. in. or less). 

Provide a 3-valve by-pass as shown, the valve in front of the reducing valve to be 
of the globe pattern. Run a "control pipe" as shown. Place a low-pressure gauge and a 
%-inch pop alarm valve set at 10 lb. pressure in the heat main about 10 feet from the 
discharge of pressure-reducing valve. 

Risers: A system of supply and return risers is to be run as shown on plans. Risers 
are to be run [exposed] [concealed] and are to be of sizes marked on plans. All radiator 
branches must grade back to risers or mains with as much grade as possible, in no case 
less than 1 inch in 5 feet. All connections are to be made with ample provision for expan- 
sion and contraction and particular care is to be taken that branches are run without pockets. 

Return Piping: All return risers and branches are to connect into return mains. 
Horizontal return piping must be graded toward the vacuum pump not less than 1 inch 
in 40 feet. 

Dirt Traps : The bottom of all supply connections taken from the heating main must 

24—2 



be dripped into the vacuum return by means of a cooling leg, a gate valve, a Webster 
Dirt Strainer and a Webster Return Trap of size shown on plans. 

Nole : In large installations it is advisable to run a separate gravity drip line and connect drip of 
each riser or drip point of main through 'H in. line with gate valve to this line. The discharge of this 
gravity drip line to be to the feed-water heater through loop seal or to the vacuum return through heavy- 
duty trap. 

Dirt Strainers: Provide and connect Webster Dirt Strainers of the sizes specified 
and at the points indicated on the plans. 

Lift Fittings: Where lifts occur in the vacuum return lines they are each to be pro- 
vided with a pair of Webster Lift Fittings of the sizes called for on plans and connected 
according to special service detail furnished by the manufacturer. 

Boilers : (Here specify the make, size and type of boiler or boilers required ; also the 
CLjuipment required for the complete boiler plant, including smoke breeching, damper 
regulator, gauges, feed pump, injector and any other necessary accessories.) 

Vacuum Pumps; (Here specify the make, size, type and number of pumps required 
"to be furnished upon (concrete or other material) foimdations to be provided by this 
contractor." Detail specifications of pumps should describe either the electric-driven type 
(Nash, etc.) or the steam-driven type (Blake Knowles, Burnham, Marsh, etc.). For steam- 
driven pump, specify "simplex, double-acting type, brass lining, and fitted for hot-water 
service" and that "each pump shall be provided with a Detroit double-connected lubricator.) 

Each pump shall have ample capacity for handling the products of condensation from 
the entire heating system. 

In the suction of the vacuum pump, which must be connected to the returns from the 
heating system, a Webster Suction Strainer must be installed. This connection must be 
provided with by-pass to sewer or drain. 

The discharge from steam-driven vacuum pump must be connected to the proper 
tapping in the receiving tank. 

All connections must be properly valved and made complete. 

Suction Strainer: In the suction pipe to the vacuum pump, place a Webster Suction 
Strainer. This strainer must be connected to accord with special service detail furnished 
by the manufacturer. 

Vacuum Governor: In the steam connection to vacuum pump below the lubricator 
there must be placed a . . . inch Webster Vacuum-pump Governor with 3-valve by-pass. 
Same must be connected by means of 3^-inch vacuum line to the suction strainer and also 
to the vacuum gauge on board. Each branch must be provided with a globe valve. 

Gauges: Furnish and erect at convenient position two 53/^-inch compound gauges 
mounted on a slate board. Connect one gauge to equalizing line between heat main and 
reducing valve, one gauge to a line connecting vacuum governor with vacuum return at 
suction strainer. All gauge piping to be )^-inch and all branches valved. 

Air-separating Tank: Furnish a Webster Air-separating Tank ... in. in diameter 
by . . . in. long. 

Erect the separating tank as high above the heater as possible, as shown on plans, 
and to it make connections from discharge of vacuum pumps and to feed-water heater 
through long loop seal. 

From top outlet on tank make a IJ^-in. vent connection to atmosphere. 

Feed-water Heater: Furnish and erect on foundation one Webster Feed-water 
Heater of sufficient capacity for heating the required feed water to within 5 deg. of the tem- 
perature of the steam entering same. 

The drip from oil separator is to connect to waste line through a Webster Grease Trap 
with ,3-valve by-pass. 

The contractor is to make all necessary steam, water and drain connections as shown 
or called for. 

Steam Separator: Furnish and connect Webster Steam Separator of approved type 
to steam lines as shown or called for. 

The drip from bottom of each separator is to be connected into a high-pressure trap 
of approved make. Each trap is to be provided with a 3-valve by-pass. The discharge 
lines from these traps are to be connected into the feed-water heater. 

Covering: After all piping and apparatus has been tested and made tight to the 

24^3 



approval of the architect or liis representative, the following covering is to be applied. 
(Here specify necessai'y covering for boilers, heater, separator, and all (specify which) 
piping, valves and fittings.) 

Painting and Bronzing: All radiators, coils and exposed piping throughout the build- 
ing, after being tested, are to be painted or bronzed 2 coats as follows: 

All radiators, coil and exposed piping are to be painted 1 coat of sizing and then bronzed 
or painted; color as selected by architect or owner. 

All exposed parts of boiler and heater to be painted 2 coats of black asphaltum paint. 

Tests: The system shall be tested under 15 lb. steam pressure. 

Washout caps will be furnished for Webster Traps. The interiors of traps are to be 
removed, when testing and washing out system, running all condensation to waste. 

Inspection: This job is to be inspected by a representative of Warren Webster & 
Company before acceptance. 

Guarantee : The contractor must agree to make good at his own expense any defects 
in labor or material furnished by him for this work which may develop within 1 year from 
the completion of this contract. 

The entire system when completed is to be tested in the presence of the architect or 
his representative, and made tight without caulking. The contractor will be held liable for 
any damage to the building or its contents due to leaks or other defects in his work which 
may develop during the period of installation and test. 

Specifications for the Webster Moderation System of Steam Heating 

(This specification is drawn for a large residence. It is, of course, 
subject to modifications and variations for other kinds of buildings, for other 
sources of steam than house boiler, etc., for which revised typical specifica- 
tion clauses will be furnished by Warren Webster & Company on request.) 

General: (Here specify the general requirements of the contract such as intent of 
drawings and specifications; verification of measurements; co-operation with other con- 
tractors; foreman; ordinances; permits; protectionof work and buildings; rights reserved; 
extra work; return of specifications and drawings; payments, etc.) 

Cutting of Floors and Walls: The [building] [heating] contractor will cut all holes 
in floors and walls and provide trenches for piping which may be necessary for this work, 
and at completion make all repairs to floors and walls so cut. 

Scope of Work: This specification is intended to cover a 2-pipe open-return heating 
system known as the Webster Modulation System of Steam Heating. 

It is intended that sufficient radiation shall be supplied for heating the building to a 
temperatme of . . . degrees fahr. when the outside temperature is . . . degrees fahr. or a 
corresponding ecpjivalent difference in temperature, based upon all doors and windows 
being fitted reasonably tight to prevent excessive infiltration of cold air. 

Special Apparatus: The contractor is to secure from Warren Webster & Company 
the specified Webster Modulation System Apparatus which he is to erect and connect as 
part of this contract. 

Standard Apparatus: In addition to the special apparatus, this contractor is to fur- 
nish all other material and labor necessary for the complete work as shown on plans or called 
for in specifications. 

Boilers : (Here specify the meike, size and type of boiler or boilers required, specifying 
also the equipment required for the complete boiler plants, including smoke breeching and 
other necessary accessories.) 

Note: Boilers and auxiliary equipment must be installed in accordance with Warren Webster & 
Company's standard. 

Damper Regulator: Furnish one Webster Damper Regulator for each boiler; to be 
connected in accordance with the manufacturer's standard details. 

Gauges : A special compound gauge for Webster Modulation System is to be installed 
for each boiler. This gauge will be furnished by the manufacturers of the system. 

Radiators: All radiators throughout the building shall be of or equal 

approved make; all radiators to be of the hot-water type with supply tapping at top and 

24^^ 



return tapping eccentric at diagonally opposite lower corner. Radiators to be of the height 
and columns and to contain the surface indicated on plans. In no case is radiation to pro- 
ject above window sill. In connecting all radiators, the inlet end shall be placed next to 
feed risers, if possible. 

The indirect stacks are to be (make and type) cast-iron radiation, to 

be of the size and contain the number of sections as called for on plans. 

The heating contractor is to instruct the manufacturer of the radiation that same is 
to be thoroughly pickled and cleaned before shipment and that the outlets are to be plugged 
with loose wooden plugs. The manufacturer must issue his certificate to the contractor 
showing that these radiators have been so cleaned. These radiators are to be kept plugged 
until they are installed and connected. 

Air valve tappings are to be omitted and the outlets plugged. 

Radiators must be tapped or bushed for sizes of supplies and returns as shown on plans. 

Hangers : Hangers for indirect stacks are to be strong wrought-iron or pipe supports. 

Enclositres for Radiators: The enclosures and grilles for enclosed radiators will be 
furnished by '. 

Return Traps: The return end of every radiator, pipe-coil or other form of heating 
unit must be provided with a Webster Return Trap (of the type selected) . The size of the 
trap for each radiation unit shall be as shown on plan or called for in specification. The 
connections of Webster Return Traps must be made to the approval of Warren Webster 
& Company, who will provide the contractor with service details showing approved forms 
of connection. 

Supply Valves: Each radiation unit must be provided with a Webster Modulation 
Valve connected to the top supply tapping. 

The sizes of supply valves, the radiator tappings and the sizes of horizontal branches 
from risers to radiators must be as shown on plans. 

Eac^ overhead radiator must be provided with a Webster Modulation Valve with chain 
attachment. 

Provide a Webster Modulation Extended-stem Valve for each radiator behind a grille. 

Pipe: All pipe must be standard full-weight, mild-steel equal to that manufactured 
by All screwed piping must be fitted with occasional flanged unions. 

Straighten all pipe, ream all burrs and remove aU dirt before erecting pipe or fittings. 
Have all runs plumb and parallel with building. Allowance for expansion and contraction 
must be provided. Support all pipes securely and in such manner as to permit unobstructed 
movement between anchorages for expansion and contraction. 

So far as possible, all horizontal runs must be graded in the direction of steam flow; 
where this is not possible, the pipe lines shall be materially increased in size as shown on 
plans. 

Fittings: All fittings shall be best gray-iron, straight and true and free from holes or 
other defects; equal to those manufactured by Fittings shall be standard- 
weight. 

Valves: All gate valves must be equal to those manufactured by All 

check valves must be Nelson No. 85, of balanced type with vertical seat. 

Fresh-air Inlets : Fresh-air inlets for indirect heating are to be taken from openings 
provided in walls. Another contractor will provide heavy copper wire screens having 3^-in. 
mesh, and louvers over the mouth of each inlet. 

Sheet Metal Work: The ducts supplying fresh air to the indirect stacks, the indirect 
stack casings and the hot-air flue from indirect stacks to registers are to be made of gal- 
vanized iron. They are to be properly braced and locked tight to prevent air leakage. 
An adjustable lock quadrant hand damper is to be provided in cold-air connection to each 
indirect stack. 

The metal used for all ducts and flues is to conform to the following gauges: 

Ducts that have one dimension over 48 in., ... gauge. 

Ducts that have one dimension from 30 to 48 in., . . . gauge. 

Ducts that have one dimension from 12 to 30 in., . . . gauge. 

Ducts that have one dimension smaller than 12 in., . . . gauge. 

The indirect stack casings are to be made of . . . gauge iron and are to be built neatly 

24^5 



around stacks and provided with cleanout doors in bottom or side. 

Registers: The registers for the outlets of hot-air flues from indirect stacks will be 
furnished by ; their installation is included within this contract. 

Steam Piping: From the steam outlets on boiler rise and connect to a steam header 
over boiler. From top of header take branches as shown. The steam lines are to be run 
close to ceiling of cellar with a grade of 1 in. in 25 f I. The branches for risers are to be taken 
from top of mains. Stetun header and main are to be dripped to wet drip line where shown. 

Risers : A system of supply and return risers is to be run as shown. Risers are to be 
run [exposed] [concealed], and are to be of sizes marked on plans. Unless otherwise noted 
on plans, branches to radiators above first floor are to be run concealed in floor construc- 
tion and branches to first floor radiators are to be run overhead in cellar as close to ceiling 
as possible. All radiator branches are to grade back to risers or mains with as much grade 
as possible, in no case less than 1 in. in 5 ft. All connections cu-e to be made with ample 
provision for expansion and contraction and particular care is to be taken that branches are 
run without pockets. 

Return Piping : All return risers and returns from first floor radiators are to connect 
into overhead return mains. The return mains are to start as high as possible and grade 
toward the Webster Modulation Vent Trap 1 in. in 25 ft. The vent trap {or traps) to be 
located where shown and at least 30 inches above the water line and as much higher as possible. 
The vent trap is to be vented through check valve as marked on plans. Make a ... in. 
city water supply connection to boiler with cock, also a ... in. drain to waste through gate 
valve from the return header of boiler as directed. Check valves are to be instaUed where 
shown. 

A wet drip line is to be run on wall near floor as shown, and connected to boiler. To 
this line connect drips of mains, indirect radiators and lines from vent trap as shown. 

Covering: After all piping and apparatus has been tested and made tight to the ap- 
proval of the architect, the following covering is to be applied. (Here specify necessary 
covering for boilers, and all steam, return and drip piping, valves and fittings.) 

Painting and Bronzing: All radiators, coi's and exposed piping throughout the build- 
ing, after being tested, are to be painted or bronzed 2 coats as follows: All radiators, coils 
and exposed piping throughout the building eue to be painted 1 coat of sizing £uid then 
bronzed or painted; color as selected by architect or owner. 

All exposed parts of boiler to be painted 2 coats of black asphaltum paint. 

Radiators or ducts which are visible through grilles or registers are to be painted 2 
coats of dull black. 

Tests: The system shall be tested under 10-lb. steam pressure. The entire system 
shall be thoroughly washed out before final test, wasting condensation to sewer or other 
point of disposal. 

Inspection: This work is to be inspected by a representative of Warren Webster & 
Company before acceptance. 

Guarantee : The contractor must agree to make good at his own expense any defects 
in labor or material furnished by him for this work which may develop within 1 year from 
the completion of this contract. 

The entire system when completed is to be tested in the presence of the architect or 
his representative, and made tight without caulking. The contractor will be held liable 
for any damage to the building or its contents due to leaks or other defects in his work 
which may develop during the period of installation smd test. 



CHAPTER XXV 

Webster Sylphon Trap Attachments 
I. For "Sylphonizing" Webster Traps of Earlier Types 

STEAM heating, like almost every other science, has developed pro- 
gressively through experience. 

Being pioneers in this field Warren Webster & Co. have had ample 
incentive and opportimity for experimental research and development, 
and have constantly improved their product and methods, discarding and 
abandoning eairlier types of apparatus as improved forms were adopted. 
The Webster Sylphon Trap (shown and described on page 00) is now 
generally recognized by leading architects and engineers to be the most 
satisfactory type of device for return line systems. 

It is in its tenth year of success and the total number in use is rapidly 
approaching the million mark. 

Owners of buildings and plants in which old-style Webster Valves Eire 
in use wiU be vitally interested in knowing that such valves can be readily 
converted into Webster Sylphon Traps by means of the Webster Sylphon 
Attachments described in this chapter. The conversion necessary to bring 
the heating system thoroughly up to date can be made at a very moderate 
cost. No breaking or touching of pipe connections is involved, as the old 
valve bodies are utilized. 

The advantages to be derived from the "changeover" 
will be evident from the description of the Webster Sylphon 
Trap, on page 00, which description will equally fit the 
earlier Webster Valves after they are converted by means of 
Webster Sylphon Attachments. 





Fig. 25-1. The No. 422 Thermostatic VeJve in its original form and same valve changed over. 
Pipe connections untouched. 

25—1 



Conversion of No. 422 Webster Thermostatic Valves: The 
method of chEiaging over by means of the S-A-13 Webster Sylphon Attach- 
ment is indicated by the illustrations. 

It is only necessary to remove the old bonnets and interior parts, tap- 
ping the body for the insertion of a new solid brass seat by means of a tapping 
tool. The Webster Sylphon Trap Attachment may then be inserted and 
the old valve has become a new Webster Sylphon Trap equal in performance 
to the standard Webster Sylphon Traps which are furnished to thousands 
of new customers each yeeu". 

For conversion of Multiple-unit Thermostatic Valves, see page 00. 
The entire change may be made in less than five minutes. 

Conversion of Webster Motor Valves: This is accomplished 
practically the same as with the No. 422 Webster Thermostatic Valve 
(which see for description), except that a slightly different Sylphon Attach- 
ment is used. 

The illustrations show the No. 522 M Sylphon Attachments for J^- 
inch motor-valves of the disc-port type. The No. 533 M Attachment for 
^-inch motor-valves is of exactly the same construction. These same 
Sylphon Attachments may be applied to the '03 motor-valves of the pin- 
port type where this special type of valve is to be changed over. 

For conversion of Multiple-unit Motor Valves, see page 00. 





, Fig 25-2. J/^Inch Webster Motor- Valve, Disc-Port Type, in its original form and 

same valve changed over. Pipe connections untouched. 

Conversion of No. 422 Webster Water-seal Motors: The 
method of changing over, as illustrated, involves the use of the same attach- 
ment as for changing over the Webster Thermostatic Valve as just de- 
scribed. In the case of the Water-seal Motor, however, the operation is 
simplified through the old body being cdready tapped for the valve seat. 

It is only necessary to remove the old bonnets and interior parts, and 
insert the new solid brass seat. The Webster Sylphon Trap Attachment 
may then be inserted and the old valve becomes a new Webster Sylphon 
Trap. 

For conversion of Multiple-unit Motor Valves, see page 00. 

25—2 




Fig. 25-3. The No. 422 Water-seal Motor in 
its original form and same motor changed 
over. 

Pipe connections untouched 





Fig. 25-1. No. 5-C-15 Sylphon Attach- 
ment for 522 or 523 Water-seal Trap 
where the Discharge Rating is low. 



Conversion of No. 522 Water-seal 
Traps: The change-over in this instance re- 
quires only removal of the old bonnets and 
interior parts, and inserting the new Webster 
Sylphon Trap Attachments. 

The entire change may be made in less 
than five minutes. 

For conversion of Multiple-unit Water- 
seal Traps, see page 00. 

Similar Webster Sylphon Attachments can 
be furnished for all the other sizes of Webster 
Water-seal Traps as follows: 



I 





No. 522 Webster Water-seal Trap in its original form and same trap changed over, 
using 12-C-15 Sylphon Attachment for higher discharge rating. 



25--3 



^-in.- 


-523 


Webster Water-seal Trap 


34-in.- 


-533 


(( 


a 


(( (( 


1-in.- 


-534 


a 


a 


(( £( 


1-in.- 


-544 


a 


a 


a a 



IM-in.— 545 " 
The No. 522 and No. 523 take the same Sylphon Attachment. Another 
attachment apphes equally for No. 533 and No. 534. No. 544 and No. 545 
each have an individual attachment. 




Fig. 25-6. Multiple-unit Thermostatic Valve changed over. Pipe connections untouched. 
Note how intervening openings are blanked out by new cap and solid seat. 

Conversion of Multiple-unit Webster Valves of Earlier Types: 
On units of radiation beyond the capacity of a single valve it was the practice 
in the past to recommend and use a Multiple-unit Valve, made up of a 
specal body having multiple openings to receive two or more bonnets 
similar in all respects to those used in the standard single-unit valve. 

For changing these Multiple-imit Webster Valves by means of Sylphon 
Attachments, the use of No. 12-A-15 Sylphon Attachments is recommended 
for the alternate openings in the vedve body, the intervening outlets being 
plugged as shown in Fig. 26-6. 

As these Multiple Valves were made up to 6-unit, it is necessary to 
state whether the attachment is desired for 2-unit, 3-unit, etc., so that the 
proper number of attachments and sohd seats and blanking-out caps will 
be furnished. 

The Multiple-unit Valve, when changed will have capacity equal to 

2S— 4 






2-Unit 



S-Unit 



4-Umt 





5-Unit 



6-Unit 



I 



Fig. 25-7. Showing the method of applying Webster Sylphon Attachments and blanking seats 
and caps to the different multi-unit bodies 

(and possibly in excess of) the requirements for which the valve was originally 
installed. 

n. For "Sylphonizing" Radiator Outlet Valves of Other Makes 

A GREAT demand has developed for Webster Sylphon Attachments, 
not only in connection with early types of Webster Valves, but for 
other makes of valves and traps, and in the converting of old gravity 
systems in which the ordinary type of hand-wheel shut-off valve was em- 
ployed. 

To meet the requirements of a wide variety of sizes and types of valve 
and trap bodies the Attachments described in the following pages have been 
designed. The principle is the same with each attachment. The variation 
is only in the work of apphcation. 

With the instructions furnished and the tools loaned for the purpose, 
the work of Websterizing, by means of these attachments, is so simple that 
it can be done in a few minutes for each radiator, and so cleanly that there is 
no distvubance or damage to surroundings or furnishings. 

The use of these Webster Sylphon Attachments, properly apphed 
throughout the building, will often effect the same advantages as extensive 
changes in piping and at a small fraction of the cost. And further, the 
whole work of change-over can be done without interrupting the operation 
of the system as a whole. 

The Series 18 Webster Sylphon Attachments are made in two general 
forms : 

Class A in which the attachment parts are fitted in an extension body 
which screws into the old trap or valve body; and Class C in which the at- 
tachment parts are fitted into a special brass cap which is threaded to fit 
the old valve or trap body. 



25—5 



k 






Fig. 25-8. 5-A Extension Attachments (Five-fold Sylphon bellows) applied to valve bodies of various makes. 

The Class A Extension Attachments are made with extension bodies 
to receive 5-fold Sylphon Bellows (symbol 5-A) and to receive 12-fold 
Sylphon Bellows (symbol 12-A). 

The extension bodies of both the 5-A and 12-A classes are made with a 
threaded opening at the top to receive a standard cap but of varying diam- 
eters of the lower part of the body so that the lower end may be threaded 
to fit the thread of the old body. 

The illustrations show the full series of Extension Attachments from 
5-A-12 to 5-A-27 inclusive. The 12-A Extension Attachments are similarly 
made in sizes 12-A-12 to 12-A-27 inclusive, although the application of only 
two of this type are shown. 

The capacity required as indicated by tipe of radiator determines 
whether a 5-A or 12-A Extension Attachment should be used. 

It will be noted that the valve stem attached to the Sylphon Bellows 

25—6 




Fig. 25-9. Typical Class 
A Sylphon Attachments hav- 
ing extension bodies. 
12- A Extension Attachments 
(Twelve-fold Sylphon bel- 
lows). Push-fit seats are 
installed for correct final ad- 
justment. 




varies in length with the type of valve body, but is of similar design in all 
cases. 

The seat requires a httle explanation. It is impractical to use a threaded 
seat, as a constant distance must be maintained from body face to seat face 
and this cannot be done with a threaded seat because of the variations in 
the distance mentioned which will occur in bodies of same make and size. 

The seat is made to push-fit in the body opening which is previously 
prepared by reaming if necessary to the desirable diameter. Final attach- 
ment to gauge depth to meet any variation in the depth of the valve body is 
made by means of a push-in tool which we loan for the purpose. 

In the case of ordinary globe or angle valve bodies and in various makes 
of float traps where preparation in this respect was not previously provided 
the push-fit seat described above provides means to obtain the correct 
final adjustment without difficulty. 

The valve stem is a solid brass rod with a conical taper or seating and 
is of varying length as determined: (1) By the gauge depth of the old body 



I 




5-A 




12-A 



25—7 



Fig. 25-10. Typical Ehrtension bodies. 



from bonnet face to seat. (2) By the diameter of orifice in the seat; and (3) 
By the rating of the radiation unit to which the valve is connected. Where 
necessary to provide greater vapor space tlirough the neck of the valve, the 
rod is turned down to smaller diameter at such points. 




Fig. 25-11. Typical Class C Sylphon 
Cap Attachments placed entirely with- 
in the old bodies and push-fit seats in- 
stalled for correct final adjustment. 

At the left is a 5-C Attachment 
(Five-fold Sylphon bellows). 

At the right is a 12-C Attachment 
(Twelve-fold Sylphon bellows). 

Note this special case of a new 
screwed-in seat with a pushed-in fer- 
rule for insuring accurate adjustment. 



>yvw 




The Class C Cap Sylphon Attachments are designed for those forms 
of old valve and trap bodies in which the expanding member (Sylphon 
Bellows) and conical valve piece may be placed entirely within the old body 
without the use of an extension body. 

With this class of attachment it is necessary to provide a special cap, 
threaded to fit the existing body, but the design has been standardized so 
that few patterns need be used to meet a wide variety of bodies. 

The Class C Cap Attachments, like the Extension Attachments, are 
made to receive either the 5-fold or 12-fold Sylphon Bellows to which the 
symbols 5-C and 12-C are given. 

The illustrations on page 00 show the application of Class C Cap At- 
tachments to two different shapes of valve bodies. 

The description given previously in reference to the valve stem and seat 
for the Extension Attachments, applies equally to the Cap Attachments, 



25—8* 



CHAPTER XXVI 
Fuel Saving by Preheating Boiler-Feed Water 

WHERE exhaust steam is available and would otherwise be wasted, 
a considerable saving of fuel may he effected by utilizing a direct- 
contact (open) feed-water heater to transfer heat from the exhaust 
steam to the cold feed water. 

The saving amounts to approximately one per cent of fuel for each 11 
degrees increase in the feed-water temperature. This is the figure taken 
for ordinary calculations. 

A more accurate method of computing this saving takes into considera- 
tion the total heat in the steam generated in the boiler, as well as the final 
and initial temperatiu-es of the feed water. 
This formula is 

T. , , . . . 100 (ti - 1^) 

1 otal savmg m per cent = „ , oo — T — 

in which 

H = total heat above 32 deg. fahr. per pound of steam at the boiler 

pressure, 
ti = temperature of water after heating. 

Table 26-1. Percentage of Total Heat of Steam Saved per Degree Increase in 
Feed-water Temperature for Various Pressures of Saturated Steam 









( 


Gauge Pressure in 


Boiler — Pounds Per Sq. In. 








^fi 





10 


25 


50 


75 


100 


125 


1.50 


175 


200 


225 


^i 










Value of H 










a fee 


1150.4 


1160.2 


1169.2 


1178.4 


1184.3 


1188.8 


1192.2 


1195.0 


1197.3 


1199.2 


1200.9 


32 
40 


.0869 
.0875 


.0862 
.0868 


Per 

.0855 
.0861 


Cent Saved Per Degree Increase in 
.0849 .0844 .0841 .0839 
.0854 .0850 .0847 .0844 


Temperature 
. 0837 . 0835 
. 0843 . 0841 


. 0834 
.0810 


.0833 
.0839 


50 
60 
70 


.0883 
.0891 
.0899 


.0875 
.0883 
.0891 


.0869 
.0876 
.0884 


.0862 
.0869 
.0877 


.0857 
.0865 
.0872 


. 08.54 
.0862 
.0869 


.0852 
.0859 
.0866 


.0850 
.0857 
.0864 


.0848 
.0855 
.0863 


.0817 
. 0854 
.0861 


.0846 
.0853 
.0860 


80 

90 

100 


.0907 
.0915 
.0924 


.0899 
.0907 
.0916 


.0892 
.0900 
.0908 


. 0884 
.0892 
.0900 


.0880 
.0888 
.0896 


.0877 
. 0884 
.0892 


.0874 
.0882 
.0889 


.0872 
.0879 
.0887 


.0870 
.0878 
.0886 


.0869 
.0876 
.0884 


.0867 
.0875 
.0883 


110 
120 
130 


.0932 
. 0941 
.09.50 


.0924 
.0933 
.0941 


.0916 
.0925 
.0934 


.0909 
.0917 
.0925 


.0904 
.0912 
.0921 


.0900 
.0909 
.0917 


.0897 
.0906 
.0914 


.0895 
.0903 
.0912 


.0893 
.0902 
.0910 


.0892 
.0900 
.0908 


.0891 
.0899 
.0907 


110 
150 
160 


.09.59 
.0968 
.0978 


. 09.50 
. 0959 
.0969 


.0942 
. 0951 
.0960 


.0934 
. 0943 
.0952 


.0929 
.0938 
.0947 


.0925 
.0935 
. 0943 


.0922 
.0931 
.0940 


.0920 
.0929 
.0937 


.0918 
.0927 
.0935 


.0916 
.0925 
.0934 


.0915 
.0924 
.0932 


170 
180 
190 


.0987 
.0997 
1.008 


.0978 
.0988 
.0998 


.0970 
.0979 
.0989 


.0961 
.0970 
.0980 


.0956 
. 0965 
. 0974 


.0952 
.0961 
.0970 


.0948 
.0957 
.0967 


.0946 
.0955 
.0964 


.0944 
.0953 
.0962 


.0942 
.0951 
.0960 


.0941 
.0950 
.0959 


200 
210 
220 


1.018 
1.028 
1.039 


1.008 
1.018 
1.029 


.0999 
1.009 
1.019 


.0990 
.0999 
1.010 


.0984 
.0994 
l.OOl 


.0980 
.0990 
.0999 


.0976 
.0986 
.0996 


.0974 
.0983 
.0993 


.0972 
.0981 
.0991 


.0970 
.0979 
.0989 


.0968 
.0978 
.0987 



26—1 



tj = temperature of water before heating. 

Example: Assume a boiler pressure of 140 lb. per sq. in. absolute, and 
initial and final temperatures of 40 deg. falu*. and 210 deg. falu". respectively. 
The total saving according to this formula is 14.359 per cent, where by the 
"one per cent for each 11-degree increase" rule, the saving for the same con- 
ditions figiues 15.45 per cent. 

For convenience the results as figured from the more accurate formula 
have been reduced in Table 26-1, to a basis of per cent of saving per degree 
increase of temperature. 

Webster Feed-water Heaters: Webster Feed-water Heaters, for 
obtaining the fuel savings just mentioned and other benefits not so easily 
measured, are made in the following types: 




Fig. 26-1. Series 100 Class B 
Webster Feed -water Heater. 



„, ^„ , Fig. 26-3. Series 400 Class EBP and 
Fig. 26-2. Series 200 Class EB and Series 500 Class EBPH Webster Feed- 
Senes 300 Class EBH Webster Feed- ^ater Heater. Preference Cut-out Type, 
water Heater. Standard Type. 
Smaller sizes. 





Fig. 26-4. Series 800 Class EF Webster 
Feed-water Heater, Standard Type. 



Fig. 26-5. Series 900 Class EFP Webster Feed- 
water Heater. Preference Cut-out Type. 



26—2 



Series 100, Class B, with overflow seal: The standard type for utilizing 
exhaust steam at atmospheric pressure and for a maximum steam pressure 
of }/2 poimd per square inch. May be operated on either induction or thor- 
oughfare principle. 

Series 200, Class EB: The standard type for use in connection with ex- 
haust steEun systems under pressures not exceeding 5 pounds per square 
inch. Best operated on induction principle. 

Series 300, Class EBH: Same as Series 200, Class EB, but suitable for 
pressures up to 10 pounds per square inch maximum. Tested to 15 pounds 
per square inch. 

Series UOO, Class EBP: Same as Series 200, Class EB, but with inde- 
pendent oil separator large enough to pm-ify aU exhaust. Specially designed 
for use with exhaust steam heating or drying systems under pressures not 
exceeding 5 pounds per square inch. 

Series 500, Class EBPH: Same as Series 400, Class EBP, but suitable 



Nole:- 

The Area of Pipe B 
to be twice that of 
Pipe A 




Note:- 
With Reciprocatino Type Boiler Feed Pumps 
allow at least 24 inches (as much more as 
practicable) from C.L. of Suction Outlet to 
Pump Valves. With Centrifugal Pumps 
Consult Pump Manufacturer. ^ l-rf=^ 



To Boiler Feed Pump^ 



s^.^-^M^S^Si^^'^^ 



3T0 Sewer 



Fig. 26-6. Webster Feed-water Heater installation in connection with a Vacuum Heating System. Wata 

iidet automatically controlled. The heater shown is of the standard type. Any other type of Webster 

Heater would be connected in the same way. 

26—3 



for pressures up to 10 pounds per square inch maximum. Tested to 15 
pounds per square inch. 

Series 800, Class EF: This type is for smaller capacities, 50 to 350 
h.p., and is similar to Series 200, Class EB, except that the shell is a one- 
piece casting and is supported by a framework made from pipe and fittings. 
It is suitable for working pressures up to 10 pounds per square inch. 

Series 900, Class EFP: Same as Series 800, Class EF, but including the 
large size oil separator and the cut-out valve. 

Webster Feed- Water Heaters, Standard Type: The heater shell 
is rectangular and made up of close-grained cast-iron plates. The exposed 
parts of the shell are protected by best quality heat-resisting graphite paint 
and all outside brass work is brightly finished. 

The heater is easily cleaned, as the interior is accessible without dis- 
turbing any of the pipe connections. The large hinged doors may be quickly 
opened, and the trays withdrawn. The lower chamber, containing the 
filter, is accessible through the filter doors. Where the doors are bolted to 




With Reciprocatinfl Type Boiler Feed Pumps 
allow at least 24 inches (as much more as 
practicable) from C.L. of Suction Outlet to 
Pump Valves. Witti Centrifugal Pumps 
Consult Pump Manufacturer 

To Boiler Feed Pump 



V]| -^=:~?, To Sewer 



Fig. 26-7. Webster Feed-water Heat«r installation in connection with a Vacuum Heating System. Water 
inlet manually controlled. The heater shown is of the standard type. Any other type of Webster Heater 

would be connected in the same way. 

26—4 



LOW PRESSURE 
RETURNS INLET 



TROUGH aWATERSEAL 
HEATING TRAYS 




OIL SEPARATOR 

^ EXHAUST 
STEAM INLET 



HI6H PRESSURE 
^RETURNSINLET 



OVERFLOW 
SINK PAN 



SKIMMER FOR 
RFACE BLOWOFF 



OIL 
5EPARAT0R0RIP 



OVERFLOW 
OUTLET 



ER SCREENS 



Fig. 26-8. Series 200 Glass EB and Series 300 Class EBH Webster Feed-water Heaters, Standard Type. 



26—5 



the heater body, the shell is suitably reinforced, the faces being machined 
to insure tight joints. 

The water supply to the heater is controlled automatically, the regulat- 
ing valve being operated by a series of levers connected to an open copper 
sink pan (performing the functions of a float), placed within the heater shell. 

Any dangerous excess of water automatically passes out of the heater 
when the water reaches the overflow level. Except in the case of the 100 
Series, the excess water is automaticaUy passed out through a valve actuated 
in the same manner as the cold water supply-valve, that is, by another open 
sink pan placed within the heating chamber. This valve is normally 



I 




Fig. 26-9. Series 800 Class EF Webster Feed-water Heater Standard Type. 



26—6 



closed, preventing loss of steam. 

The Webster Oil Separator which forms a part of each heater is well 
known and extensively used as an independent unit for removing oU from 
exhaust steam mains, hence its use in the Webster Feed-water Heater. 

The feed water, entering the heater through the automatically con- 
trolled valve inlet, passes into the water-sealed distributing trough, which 
has two wide, extended hps. The water, overflowing from this trough in 
even sheets, is distributed over a series of oppositely inchned finely per- 
forated metal trays, arranged one above the other as shown in the iUustra- 
tion on page 00. The water in its downward course falls from one tray to 
the other, part of it passing through the tray perforations and the balance 
falling from the lower edge of the tray to the tray immediately below. 

This method of water travel provides the necessary surface contact for 
the steam and water so that the highest possible temperature is imparted to 
the water, causing a liberation of gases and precipitation of solids. Anaple 
space is provided to insure uniform distribution of the steam around the 
trays. 

By reason of the large storage chamber it is possible to utilize the heater 
as a "receiver" for condensation from heating systems, dry kilns, heating 
apparatus, etc. Between the level at which the cold water supply-valve is 
closed and the overflow level there is ample space for the accumulation and 
storage of such returns. 

The filter is located in the lower compartment of the heater. In this 
setthng chamber, opportunity is given for the precipitation and filtration 
of the particles of sediment and impurities and for frequent drEiinage through 
a quick-opening drain valve. 

The filter bed is commonly composed of coke or other suitable material, 
which is contained between the perforated division screens already mentioned. 
This material can be renewed whenever necessary. 

The large doors at the front allow ready access for charging and cleaning. 

The Webster Preference Cut-Out Heater: This type, as may be 
noted from the illustrations, combines a Webster Heater and a IcU-ge oil 
separator with a cut-out gate valve intervening. The oil separator has 
sufficient capacity to remove the oil from the exhaust steam delivered from 
the engines, pumps and other som-ces. This arrangement is therefore 
especially desirable where exhaust steam is to be utilized in heating or drying 
systems, cooking kettles or other industrial processes. 

A Webster Grease Trap is used in draining the separator. Steam from 
the engines and auxiliaries should be combined in a common exhaust pipe 
before reaching the heater. This exhaust pipe may enter the separator 
horizontally or vertically, the latter condition being usual with the exhaust 
steam current upward. 

Upon reaching the preference oil separator the steam flows horizontally 
through the baffles, which are of the standard Webster design (see Figure 
00-00), comprising a number of hooked steel plates interposed in the course 
of the steam, causing separation by contact, by change of direction and by 
adhesion. The ports through which the steam is guided and the free 

26—7 



Eirea through the baffles are especially designed to prevent any considerable 
loss of pressure. 

After passing through the baffles, the steam may pass to the heater, or 
to the outlet into the heating system or other apparatus using exhaust 
steam, or to the atmosphere. 

Particularly valuable advantages of the Webster Preference Cut-Out 
Heater are: 

1. The considerable saving in piping connections and additional ap- 
paratus which may be accomplished by its use as compared with the Steuidard 
Heater. 

2. The cut-out valve used in the Webster Preference Cut-Out Heater 

WAT[R INL[I REGULATING VALVE 

LOW PRESSURE . 

EXHAUST 
STEAM INLET 




BAFELE 
..WEBSTER 
PREFERENCE 
SEPARATOR 



»MER FOR SURFACE 
BLOWOFP 



drain; 
5creen for pump 



CHAMBER 



FILTER CHAMBER 



Fig. 26-10. Series 400 Class EBP and Series 500 Class EBPH Preference 
Cut-out Type Webster Feed-water Heaters. 



is most: reliable for its purpose. When the heater is cut out for internal 
inspection or cleaning, the course of the exhaust steam through the oil 
separator is such that no steam is in contact with the side wall of the heater. 
Steam passes through the separator and on to atmosphere or the heating 
system without w arming up the lieater body to a degree that would endanger 
or discomfort the man who may have to enter. A thorough clean-out is 
possible at any time without having to wait until the whole plant is shut 
down. 

3. The grease and oil trap too is not integral with the overflow of the 
heater, so thaj if its outlet becomes temporarily deranged, oil cannot get. 
ba3k into the heater through the overflow opening. 



I 



Fig. 26-11. Series 900 Class £FP Preference Cut-out Type Webster Feed-watef Heater, 
-9 



Table 26-2. Dimensions of Series 200, Class EB, Webster Feed-water Heaters 

For working pressure up to 5 pounds per square inch 
SPECIFICATIONS 





CAPACITY * 






HEATING TRAYS 


CUBIC CONTENTS 






WEIGHTS, LBS. 








Drawing 
No. 












Wl£g. 

Pres. 






No. 




Lb. 




Ma- 


Total 


Water 


FUter 








Horsepower 


Min. 




Sq. In. 


terial 


Cu. Ft. 


Cu. Ft. 






Shipping 


Max. 


203 


to 400 


;^ 


9247 


12.5 


h 


24.25 


14.7 






2600 


3600 


205 


425 to 650 


II S 


9203 


16.5 




40.75 


25.5 




JS 


3700 


5400 


207 


675 to 900 


.it 


9250 


24.0 


t^ 


60.2 


40.0 


& 


5 


4700 


7300 


210 


925 to 1350 


9254 


33.0 


A 


81.6 


52.0 


s. 




5700 


9000 


215 


1375 to 1850 


9252 


51.6 


o Si 


121.3 


80.0 


f^ 


ri^ 


8000 


13100 


220 


1875 to 2400 


« o 


9257 


63.8 




151.6 


104.0 


1 


S3 


9000 


15700 


225 


2425 to 3000 


9256 


82.0 


180.0 


128.1 


CL| 


10300 


18400 


230 


3100 to 4000 


3» 


22457 


95.7 


S" 


214.0 


133.5 


a 


T3 

g 


13000 


21300 


235 


4100 to 5500 


^^ 


13377 


121.5 


o 


242.0 


140.0 


S 


15000 


23600 


250 


5600 to 7500 


"ort 


13626 


160.1 


s 


318.5 


179.0 


Q 


O 


20000 


31400 


285 


7600 to 9500 


d'S 


22196 


201.5 


i 


400. 


222.0 




fe 


22000 


36000 


299 


9600 to 12000 


Z 


18779 


243.0 


485.3 


268.0 




ira 


25000 


41700 



* One rated horsepower-capacity for heating 30 pounds of water per hour from 40 degrees faiir. 
to a temperature within 5 degrees of the steam temperature. 









CONNECTIONS 




No.. 






® 


® 


® 


® 


® 


® 


® 


®|® 


203 e'l 
205! 8llH 
207| 8l2 
210,10|2 


4 
4 
5 
5 


2K. 
3)^ 


1^ 

1 

1 


2 
2 


2H 
3 
4 
5 


2^ 
2H 

3 


1 


215112121^ 
220:14l2H 
2251163 
230!l8!3 


6 
6 

8 
8 


4 
4 
5 
6 


1 

iM 
IK 
1J€ 


2)4 
3 
4 
4 


5 
5 
5 

2-5 


3 
5 
5 


IK 


235204 
25022 5 
28524 5 
299 286 


10|8 

108 
12!8 
12!lO 


IK 

2-m 
2-m 


5 i2-35 IH 
5 12-35 ilH 
5 12-46 (2 
5 ;2-68 '2 



Live Steam Drips 



J Exhaust Inlet 




DD 



D 



D 



)=0 §<— -Oil Separator 
Drips 



Don 



D 



n D 



Fig. 26-12. 



No. 


TRAYS 


FOUNDA- 
TION 


OVER- • DIMENSIONS 




No. 1 Size 


Lg. 


Wd. 


Hgt.iA 


A' 


B 


c 


° 


E F 


G 1 H 


J 


E 


L 


M 


N 


P 


R 


203 

205 

- 207 

210 


5 
5 
6 
12 


15 x24 
15Hx30H 

16 x36 
10 x40?^ 


35 
41 
45 
51 


35 
41 
45 
51 


&0% 

88 
1015^ 
1015^ 


26 
32 
36 
42 


26 
32 
36 
42 


80M 

88 
1015^ 
101 J^ 


66 
72 
84 
84 


54H 
575^ 

ma 

67M 


7H514 

7K6 

7K6 


79?i21H 

93K25 

93K28 


9 

iiH 

13M 
15jl 


22 
27 
28M 
31K 


22 
25M 
27 J^ 
31M 


25K 
2SH 
34 
37 


16 
19H 
21H 
245/8 


5M 

7M 

m 


7K 
8H 

11 

10J4 


215 
220 
225 
230 


12 
12 
24 
18 


13^x46 
16Mx47 
17^x28 
16Mx47 


57 
69 
69 
93 


57 
57 
66 
57 


115H 
115H 
117M 
115M 


48 
48 
57 
48 


43 
60 
60 
84 


115H 
115K 
mVi 
115M 


96 
96 
96 
96 


77M 

815^8 

82H 
77 


8M|7 
8Mi7 

9 m 

9 pK 

12H?M 
11H,9K 

....9H 

.... 8}^ 


10m?3H 
105)^40 
106>^:43 
105Hj52 


16 
18 
19M 
20 


36 

im 

42 
57 


365i 
45 
42^ 
55 


41 J^ 
47H 
46K 
53K 


27H 
33M 
33 H 
45H 


1^^ 

lOJi 

UK 


135^ 
13?i 
16 
12K 


235 

2.50 
285 
299 


24 

48 
48 
48 


15^x47 

15J4x31 
15}^x39 
15>^x47 


105 
105 
105 
105 


57 

72 
89 
105 


1205^ 

122K 
1229^ 
124H 


48 
63 
80 
96 


96 
96 
96 
96 


1205^ 

122J^ 
1223^ 
124H 


96 
96 
96 
96 


77 
75 
75 
75 


105K61K 
107J^ 61 
107H61U 
107M 61 H 


23H 

25K 

27 

40 


64 
65 

65 
65 


61 
67M 

67 K 
6714 


63H 
63H 
631^ 
67H 


51% 


12 
12 
12 
12 


13?i 

20 

16 

365^ 



All sizes and dimensions in inches. 

Note: The above data (except weights) apphes also to extra heavy 300 series Class EBH Heaters for 
working pressures up to 10 pounds per square inch. 



26—10 



Table 26-3. Dmien8ion8 of 400 Series Class EBP Webster Feed-water Heaters 

For working pressure up to 5 pounds per square inch 
SPECIFICATIONS 





CAPACITY* 


Drawing 
No. 


HEATING TRAYS 


CDBIC CONTENTS 


FUter 


Wkg. 
Press 


WEIGHTS LBS. 


No. 


Horsepower 


Lb. 

Min. 


Area 
Sq. In. 


Ma- 
terial 


Total 
Cu. Ft. 


Water 
Cu. Ft. 


Shipping 


Max. 


403 
405 
407 
410 
415 


to 400 

425 to 650 

675 to 900 

925 to 1350 

1375 to 1850 


No. of lbs. 
per Min. = H 

of rated 
Horsepower 


13166 
13188 
13167 
13165 
13171G 


12.5 
16.5 
24.0 
33.0 
51.6 


American 
Ingot Iron 
or Copper 


24.25 
40.75 
60.20 
81.60 
121.30 


14.7 
25.5 
40.0 
52.0 
80.0 


13 

1" 


m £ 

■8 a 
§&■§ 


3500 
4950 
6700 
8050 
10800 


4500 

6650 

9300 

11350 

15900 



* One rated horsepower = Capacity for heating 30 pounds per hour from 40 deg. Fahr. to a 
temperature within 5 degrees of the steam temperature. 



Returns- 
Inlet 

© 



^Live Steam Drips 




DIAGRAM FOR PREFERENCE OIL SEPARATORS 
CLASS H CUSS C 




Exhaust Inlet 

® 

Note;- The Table of Dimensions 
below reters to Heaters with 
Standard Equipment. 
Separators smaller or larger 
than Standard will be furnish' 
ed it desired. The table at 
right shows sizes of all Preier 
ence Oil Separators which 



,, u^ ,, -- , |x N WEBSTER 

'^ ^^ '1^ ^1 \ GREASE TRAP can be used with this type 

DIAGRAM FOR STANDARD^OvertlowQ Heater 



PIZE 


C4PAC1TY 


DIMENSIONS 


SIZE 

DRIP 


'"^PEfl'^MIN. 


Q 


R 


s 


T 


U 


fi 


46 


8 


11 


13 


OX 


10 \ 


1 


S 


80 


9'f 


12;,- 


U 


u 


ii'v: 


1 


10 


12,5 


UK 


n% 


17K 


14)4 


14 


1 


12 


175 


ny. 


15H, 


l.S 


im 


lo'A 


1 


11 


255 


15 


18 


23 


V->!< 


lS!t 


IH 


16 


335 


v,% 


31 


27;<f 


22 W 


22 


m 


IS 


375 


I'J* 


24 


2'J* 


21>i 


23 ;V 


w 


20 


476 


20)4 


■2i,% 


30 3£ 


2d'4 


U% 


w 



EQUIPMENT 



Fig. 26-13. 





STANDARD i CONNECTIONS 


TRAYS 


FOUN- 






EQUIPMENT 






DATION 




o 






















« 


to 


Size 
Sep'r. 
Size 
Valve 

Size 
Trap 


© 


® 


® 


® 


® 


® 


® 


® 


® 


i 

5 


Size 


.d 






403 


10 


fi 


1 


10 


1 


4 


2V, 


V, 


W, 


2K 


2V. 


1 


15 x24 


35 


35 


80% 


405 


12 


8 


1 


12 


IV, 


4 


3 


1 


1/4 


3 


•IV- 


1 


5 


15Hx30H 


41 


41 


88 


407 


It! 


K 


\v. 


lb 


2 


5 


■.w. 


1 


2 


4 


■i, 


1 


6 


16 x36 


45 


45 


lOlH 


410 


IH 


10 


IVo 


18 


2 


5 


■AV, 


1 


2 


5 


3 


1 


1^10 x40?^ 


51 


51 


1015^ 


415 


2U 


12 


IH 


20 


2M 


B 


4 


1 


2K2J5 


3 


11^:12! 13^x46 


67 


57 


115}^ 





DIMENSIONS 


.H /I 
(0 


A' 


B 


C 

66 


D 


E 


F 


G 


H 


J 


K 


L 


M N 


O 


P 


V 


403 2 


6 26 


8034 


545^ 


Wi 


73 Ji 


18K 


9 


22 


17^ 


25M,16 


5% 


VA 


lOH 


405 ; 


2 32 


88 


72 


57 H 


■IV, 


tiV, 


VMM 
93M 


2m. 


IIH 


27 


20H 


28M19H 


7H 


HH 


iiH 


407 ; 


h3H 


101 H 


8469H 


IV. 


« 


25 


13»4 


28H 


22 V, 


34 i21i.g 


'JVr 


u 


iiH 


410 < 


24;^ 


101 H 


84{67M 
96,77^ 


1% 


B 


931i( 


28 


XbV, 


■ilV, 


25 V, 


37 .24^ 


8 


10^ 


13 


415 4 


T 


115H 


8H7 


104 54 


33M 


16 


36 


28 Va 


41M27H 


8M 


13M 


14 



Note: The dimenaions and data above — except weights — may be used also for the 600 Series CUss EBPH 
Extra-heavy pattern Webster Feed-water Heaters. 



26—11 



Table 26-4. Dimensions of Series 800, Class EF, Webster Feed-water Heaters 

For working pressure up to 10 povmds per square inch 
SPECIFICATIONS 





CAPACITY * 


Drawing 
No. 


HEATING TRAYS CUBIC CONTENTS 


Filter 


Wkg. 
Press 


WEIGHTS, LBS. 


No. 


Horsepower 


Lb. 
Min. 


Area 
Sq. In. 


Ma- 
terial 


Total 
Cu. Ft. 


Water 
Cu. Ft. 


Shipping 


Max. 


800 
801 

801}^ 

802 

803 


to 75 

80 to 125 

130 to 175 

180 to 260 

265 to 400 


CO rH\ 3J 


17045 
16660 
16661 
16662 
16663 


4.5 
5.0 

5.6 

9.0 

13.5 


American 
Ingot Iron 
or Copper 


7.1 

9.8 

11.6 

16.4 

22.9 


4.2 

5.9 

7.3 

11.08 

14.2 


-o 

II 




1125 
1450 
1700 
2200 
2450 


1400 
1850 
2200 
2900 
3350 



• One rated horsepower = Capacity for heating 30 pounds of water per hour from 40 degrees f ahr. 
to a temperature within 5 degrees of the steam temperature. 



Live Steam Drfps ® 
Oil Separator 
Drips 



eomb.. Vent and 
Vacuum Breaker 



Pop Alarm Valve 
Exhaust Inlet 

© 





CONNECTIONS 


Ho. 




1 


1 












(!) 


©i® 


(1) (5) 


(s) 


(!) 


(!) 


(!) 


800 


3 




2 


1V?'M 


IK 


IV^ 


i'4 


H 


801 


4 




2H 


2 


H 


m 


m 


m 


% 


801 H 


4 




3 


2 


% 


IH 


m 


w,. 




802 


t) 




3 


2 


% 


U4 


2 


!•/, 


M 


803 


6 




4 


2)/2 


% 


IM 


■iVi 


2 


1 




Pump Outlet 
® 



Fig. 26-14. 





TRAYS 


WATER LINE 


FILTER 


DIMENSIONS 


No. 


No. 


Size 


O'erPowRec. 


Th. 


At. 


Cu. 
Ft. 


A 


A' 


B 





D 


E 


F 


G H 


J 


K 


L 


M 


N 


O 


800 


4 


10x16 


39}^,35H 


32=/, 


6 


2.0 


.9 


16 


18 


62 


43K 


48 


20 v; 


S.'iW 


4'/^ 


lav; 


14 


7H 


9^4 


10H 


3K 


57 


801 


4 


10x18 


45 


3834 


35 H 


6 


2.5 


1.2 


18 


20 


68^ 


47K 


545-S 


23 


61 »4 


4V» 


19V, 


17 V« 


«H 


1034 


11% 


3V, 


631^ 


som 


4 


10x21 


47^4 


42H 


3bH 


6 


2.8 


1.4 


20 


20 


V2H 


bl 


bSy, 


23 


65 


4i/„ 


19 V, 


IV Vs 


9% 


10% 


11% 


4V, 


67Ji 


802 


4 


14x2; 


.WVt 


4«tii 


36H 


H 


3.6 


1.8 


22»4 


22»4 


79 


58 V, 


63?/, 


24 V, 


1W» 





21 


19!4 


9H 


12i!} 


12 V, 


5 


74 


803 


5 


15x2b 


66H 


SUM 


40^ 


6 


4.6 


2.4 


2654 


2&Ji 


84H 


61 


68 


271/8 


77 


5j/2 


22V3 


21^8 


lU 


13% 


13% 


5H 


79H 



All sizes and dimensione in inches. 



26—12 



Table 26-5. Dimensions of 900 Series Class EFP Webster Feed-water Heaters 

For working Pressure up to 10 pounds per square inch 

SPECIFICATIONS 





CAPACITY * 


Drawing 
No. 


HEATING TRAYS 


CUBIC CONTENTS 


Filter 


Wlig. 
Press 


WEIGHTS, LBS. 


No. 


Horsepower 


Lb. 

Min. 


Area 
Sq. In. 


Ma- 
terial 


Total 
Cu. Ft. 


Water 
Cu. Ft. 


Shipping 


Max. 


900 

901 

901^ 

902 

903 


to 75 

80 to 125 

130 to 175 

180 to 260 

265 to 400 


No. of Lbs. 
Per Min. 
Yi of Rated 
Horsepower 


17198 
16837 
16724 
17203 
17205 


4.5 
5.0 
5.6 
9.0 
13.5 


American 
Ingot Iron 
or Copper 


7.1 

9.8 
11.6 
16.4 
22 9 


4.2 

5.9 

7.3 

11.08 

14.2 


T3 


k 

rHft< 


1675 
1780 
2200 
2700 
3200 


1925 
2140 
2600 
3425 
4100 



' One rated horsepower = Capacity for heating 30 pounds per hour from 40 degrees faJir. to a 
temperature within 5 degrees of the steam temperature. 



DIAGRAM FOR PREFERENCE OIL SEPARATORS 



CUSS C 



©Comb. VenI and r ._ 
Vacuum Brtiaker (^%_ 




DIAGRAM FOR STANDARD EQUIPMENT 



Note:- 
The Table of Dimensions 
below refers to Heaters 
I witn Standard E^jipment. 
\ Separators s.-naller or 
r than Standard v 

be furnished if desired. . 

The table at right shows sizes of all 

Preference Oil Separators which 

can be used with this type Heater 



Fig, 26-15. 



SIZE 


LBS. STEAM 


DIMENSIONS 


SIZE 
DRIF 


Q 


R 


S 


T 


U 


3 


U 


■i« 


•v^r 


'iX 


65i 


6!4 


S 


t 


20 


6« 


m 


1% 


'•% 


7!i 


% 


5 


32 


7)6 





11« 


9 


S 1 


fi 


16 


S 


11 


13 


9!^ 


lOY 1 


S 


SO 


9K 


12>f 


U 


11 


11 1^ 1 


10 


12o 


11 ii 


ii;-o 


!!->« 


\it 


U i 1_J 





STANDARD 


(CONNECTIONS 


TRAYS 


FOUN- 






SQUIPMENT 






DATION 




Size 
























.- 


No. 


1% 
coco 




tOH 


® 


® 


® 


® 


® 


® 


® 


® 


® 




Size 


fl 
^ 


5 
2 




900 


4 


3 


¥ 


4 


1 


2 


IK 


¥ 


iH 


lu 


i'4 


¥ 


4 


10x16 


2fi 


23 


62 


901 


B 


4 


1 


6 




'IV, 


2 


■% 


1% 


1'/, 


IK 


1 


4 


10x18! 28 


2.5 


68K 


901^ 


S 


4 


1 


« 




•i 


2 




m 


IK 


IK 


1 


4 


10x20 28 


27 


72K 


902 


K 


,•> 


1 


X 




H 


2 


%. 


w^ 


2 


IK 


1 


4 


14x23; 30 


3(1 


79 


903 


10 


6 


1 


10 




4 


2H 


H 


m 


2H 


2 


1 


5115x26 33 


33 


84H 





DIMENSIONS 


Size 






























No. 




































A 


A' 


B 


C 


D 


E 


F 


G 


H 


J 


K 


L 


M 


N 


o 


P 


900 


Ifi 


18 


62 |43k!48 20K 


55^i3i418K14 


7K 


95< 


lOM 


3;i 


57 


8 


901 


18 


20 


6SH 47^,54^23 


6m\3Va\W]4 


13 


9% 


10% 


113^3% 


63K 


9 


901H 


20 


20 


72Hl51 I58K23 


65K 4Ji 19J^ 


im 


9% 


10% 


11J^!4K 


6VH 


9 


902 


22»/f 


22% 


79 56H63^24K 


715^!5 21 


13H 
16!l 


9J^ 1234112^5 


74 


10 


903 


25% 


25MI84KI61 !68 27^ 

1 i 1 . 


77 I5K22J^ 


10 'IZUhzYs^SVil^ya 

1 1 1 1 


lOK 



All sizes and dimensioiiB in inolies. 



26—13 



THE WEBSTER-LEA HEATER METER 

THIS apparatus is a practical combination of the thoroughly efficient 
Webster Feed-water Heater of the rectangular cast-iron type, with the 
Lea V-Notch Recording Meter so arranged that either imit may be 
operated with equal efficiency, either in combination with or independently 
01 the other. 



Pig. 26-16. Typical \Vefj?fer-Lea llcatsr Metei'< 
26—14 



Besides heating the boiler feed water to the boiling point, this apparatus 
indicates the actual amount of boiler evaporation. Its continuous meter 



Fig. 26-17. Typical chart from a Webster-Lea Heater Meter. 

records show up careless or improper firing methods, leakage, condensation 
due to poor installation, inferior coal and in other words, act as a check upon 
the general efficiency of the entire boiler plant. 

The chai'ts (Fig. 26-17) can be integrated by means of a standard 
planimeter, such as used for engine indicator charts, and an integrating at- 
tachment giving the total flow for any period is supphed. The readings from 
the integrating attachment indicate approximately quantities of water which 
have passed over the weir. 

Where it is desired to have a record of the feed water temperature on 
the same chart with the meter record, a special attachment can be fitted to 
£uiy standard instrument. The meter chart and drum are made wider to 
provide V/i inches for temperature calibrations. This space has twenty- 
five equal divisions cahbrated in any 50 or 100 deg. interval specified. For 
example, the range may be 175-225 deg. or 150-250 deg. or 100-150 deg., etc. 



26—15'' 



CHAPTER XXyil 
Miscellaneous Useful Information 

THE tables in the following pages cover many subjects on which the 
Heating Engineer mnst have readily available data. They have been 
selected after careful consideration and will be found reliable and suf- 
ficiently accurate in every respect to meet the requirements of good practice 

Table 27-00. Space Required for Branch Connections 



From Compilation of 
F. D. B. Ingalls, M. E., 
in Model Boiler Manual 

Minimum Height of Connections off Pipe Mains 





2 


1 


3^ 


2^ 


3M 


3f* 


5 


1 


2 


2 


IH 


3H 


25^ 


3J^ 


4A 


5ii 


IM 


2 


2 


W2 


4 


.2H 


4A 


4if 


61^ 


iy2 


2 


2^ 


1 


3M 


2fi 


3ii 


4M 


5^ 


1 


2H 


2}i 


1J4 


4A 


2% 


4>^ 


4^ 


6A 


IM 


2>^ 


2J^ 


IJ^ 


43/g 


3^ 


4M 


5t^ 


6^ 


1}^ 


2J^ 


2M 


2 


4Ji 


3A 


5^ 


5K 


7t^ 


2 


2J^ 


3 


1 


4,^ 


2J^ 


3M 


4fi 


51i 


1 


3 


3 


IM 


m 


3^ 


4ii 


5^ 


6^^ 


IM 


3 


3 


W2 


4H 


3A 


4ii 


5^ 


6J^ 


l>^ 


3 


3 


2 


5,% 


3H 


5^ 


6,^ 


IVs 


2 


3 


3 


2^ 


5A 


3il 


6 


6il 


SVh 


2^ 


3 


3>i 


1 


4|i 


3^5 


4^ 


4-1 


5fi 


1 


W2 


3J^ 


IM 


4|i 


3A 


4,% 


5-4 


6f* 


IJ^ 


W2 


Wi 


1}^ 


4fi 


3M 


4f 


5-1 


7^ 


IH 


W2 


Wi 


2 


5M 


3J^ 


5^ 


6^ 


8A 


2 


W2 


3V2 


2J^ 


5|} 


4H 


6,^ 


7^ 


9A 


2J^ 


3^ 


4 


1 


4ii 


3,^ 


4-i 


5^ 


6A 


1 


4 


4 


IM 


5 


3M 


4^ 


5M 


7 


IM 


4 


4 


m 


5i^ 


3^ 


5^ 


63^ 


7J^ 


1}^ 


4 


4 


2 


5ff 


4H 


5i* 


61f 


8^ 


2 


4 


4 


2^ 


6i^ 


■4J^ 


61^ 


7,^ 


9^ 


2J^ 


4 


5 


1J€ 


5|| 


3M 


5A 


6^ 


7M 


1^ 


5 


5 


IJ^ 


51^ 


4^ 


5H 


6-li 


8A 


IM 


5 


5 


2 


6M 


m 


6A 


7B 


93V 


2 


5 


5 


2J^ 


6fJ 


m 


6^ 


7fi 


lOjV 


2}^ 


5 


6 


1^ 


6A 


iVs 


ZVs 


6t% 


8A 


IM 


6 


6 


IH 


6V2 


m 


6 


7^ 


8H . 


13^ 


6 


6 


2 


7 


4f| 


6fi 


8 


9^ 


2 


6 


6 


2J^ 


7?^ 


5^ 


7^ 


&% 


loa 


2}^ 


6 


8 


2 


8M 


5M 


7M 


9li 


10^ 


2 


8 


8 


2H 


8^ 


61/g 


8^ 


^Vs 


11-1 


2J^ 


8 


8 


3 


9 


65^ 


8M 


103^ 


12M 


3 


8 



27—1 



Table 27-00. Dimensions of Standard Wrought-Iron Pipe * 

Black and Galvanized for Temperatures up to 450 deg. 



1^ and smaller proved to 300 pounds per square inch by hydraulic pressure. 
IH and larger proved to 500 pounds per square inch by hydraulic pressure. 



Nominal 
Diameter 


Actual 
Outside 
Diameter 


Actual 

Inside 

Diameter 


Inside 

Circum- 
ference 


Outside 
Circum- 
ference 


Length of 
Pipe per 

Sq. Ft. 
of Inside 

Surface 


Length of 
Pipe per 

Sq. Ft. of 
Outside 
Surface 


Inside 
Area 


Outside 
Area 


Length of 
Pipe Con^ 
taining One 
Cubic Foot 


Weight 
per Ft. 


In. 

Vs 
H 
H 


In. 

0.405 
0.54 
0.675 
0.84 


In. 

0.270 
0.364 
0.494 
0.623 


In. 

0.848 
1.144 
1.5.52 
1.957 


In. 

1.272 
1.696 
2.121 
2.652 


Ft. 

14.15 

10.50 

7.67 

6.13 


Ft. 
9.44 

7.075 
5.657 
4.502 


In. 

0.0.572 
0.1041 
0.1916 
0.3048 


In. 

0.129 
0.229 
0.358 
0.554 


Ft. 
2500. 
1385. 
751.5 

472.4 


Lb. 
0.243 

0.422 
0.561 
0.815 


1 


1.05 
1.315 
1.66 
1.90 


0.824 
1 . 048 
1.380 
1.611 


2.589 
3.292 
4.335 
5.061 


3.299 
4.134 
5.215 
5.969 


4.635 
3.679 
2.768 
2.371 


3.637 
2.903 
2.301 
2.01 


0.5333 
0.8627 
1.496 
2.038 


0.866 
1.357 
2.164 
2.835 


270. 

166.9 
96.25 
70.65 


1.126 
1.670 
2.2.58 
2.694 


2 

3 

3M 


2.375 
2.875 
3.50 
4.00 


2.067 
2.468 
3.067 
3.548 


6.494 

7.754 

9.636 

11.146 


7.461 

9.032 

10.996 

12.566 


1.848 
1.547 
1.245 
1.077 


1.611 
1.328 
1.091 
0.955 


3.355 
4.783 
7.388 
9.887 


4.430 

6.491 

9.621 

12.566 


42.36 
30.11 
19.49 
14. 56 


3.600 
5.773 
7.547 
9.0.55 


4 

5 
6 


4.50 
5.00 
5.563 
6.625 


4.026 
4.508 
5.045 
6.065 


12.648 
14.153 
15.849 
19.054 


14.137 
15.708 
17.475 
20.813 


0.949 
0.848 

0.757 
0.63 


0.849 
0.765 
0.629 

0.577 


12.730 
15.939 
19.990 
28.889 


15.904 
19.635 
24.299 
34.471 


11.31 
9.03 
7.20 
4.98 


10.66 
12.34 
14.50 
18.767 


7 

8 

9 

10 


7.625 
8.625 
9.625 
10.75 


7.023 

7.982 

9.001 

10.019 


22.063 
25.076 
28.277 
31.475 


23.954 
27.096 
30.433 
33.772 


0.544 
0.478 
0.425 
0.381 


0.595 
0.444 
0.394 
0.355 


38.737 
50.039 
63.633 
78.838 


45.663 
58.426 
73.715 
90.762 


3.72 
2.88 
2 26 
1.80 


23.27 
28.177 
33.70 
40.06 


11 

12 
14 
15 


12.00 
12.75 
14.00 
15.00 


11.25 
12.000 
13.25 
14.25 


35.343 
38.264 
41.268 
44.271 


37.699 
40.840 
43.982 

47.124 


0.340 
0.313 
0.290 
0.271 


0.318 
0.293 
0.273 
0.254 


98.942 
116.535 
134.582 
155.968 


113.097 
132.732 
153.938 
176.715 


1.455 

1.235 

1.069 

.923 


45.95 
48.98 
53.92 
57.89 


16 
18 
20 


16.00 
18.00 
20.00 


15.25 
17.25 
19.25 


47.274 
53.281 
59.288 


50.265 
56.548 
62.832 


0.254 
0.225 
0.202 


0.238 
0.212 
0.191 


177.867 
225.907 

279.720 


201.062 
254.469 
314.160 


.809 
.638 
.515 


61.77 
69.66 

77.57 



* Walworth Manufacturing Company 

Table 27-00. 



Dimensions of Black and Galvanized Wrought-Iron Pipe 
Extra Strong and Double Extra Strong 







EXTRA STRONG ' 




DOUBLE EXTRA STRONG 




Size 


Diameters 
Estemal Internal 


Thickness 


Weight 

per Foot 

Plain Ends 


Diameters 
External Internal 


Thickness 


Weight 

per Foot 

Plain Ends 




.405 
.540 
.675 
.840 


.215 

.302 
.423 
.546 


.095 
.119 
.126 

.147 


.314 

.535 

.738 

1.087 


.840 


.252 


.294 


1.714 


H 
1 

\V2 


1.050 
1.315 
1.660 
1.900 


.742 

.957 

1.278 

1.500 


.154 
.179 
.191 
.200 


1.473 
2.171 
2.996 
3.631 


1.050 
1.315 
1.660 
1.900 


.434 

.599 

.896 

1.100 


.308 

• .358 

.382 

.400 


2.440 
3.659 
5.214 
6.408 


2 

2Ji 
3 
3H ■ 


2.375 
2.875 
3.500 
4.000 


1.939 
2.323 
2.900 
3.364 


.218 
.276 
.300 
.318 


5.022 

7.661 

10.252 

12.505 


2.375 
2.875 
3.500 
4.000 


1.503 
1.771 

2.300 
2.728 


.436 
.552 
.600 
.636 


9.029 
13.695 
18.583 
22.850 



27—2 



Table 27-00. Dimensions of Black and Galvanized Wrought-Iron Pipe 
Extra Strong and Double Extra Strong — Continued 







EXTRA STRONG 






DOUBLE EXTRA STRONG 




Size 


Diameters 




Weight 


Diameters 




Weight 








Thiclmess 


per Foot 






Thiclmess 


per Foot 




External 


Internal 




Plain Ends 


External 


Internal 




Plain Ends 


4 


4.500 


3.826 


.337 


14.983 


4.500 


3.1.52 


.674 


27.541 


4H 


5.000 


4.290 


.355 


17.611 


5.000 


3.580 


.710 


32.530 


5 


5.563 


4.813 


.375 


20.778 


5.563 


4.063 


.750 


38.552 


6 


6.625 


5.761 


.432 


28.573 


6.625 


4.897 


.864 


53.160 


7 


7.625 


6.625 


.500 


38.018 


7.625 


5.875 


.875 


63.079 


8 


8.625 


7.625 


.500 


43.388 


8.625 


6.875 


.875 


72.424 


9 


9.625 


8.625 


.500 


48.728 










10 


10.750 


9.750 


.500 . 


54.735 










U 


11.750 


10.750 


.500 


60.075 










12 


12.750 


11.750 


.500 


65.415 










13 


14.000 


13.000 


.500 


72.091 










14 


15.000 


14.000 


.500 


77.431 










15 


16.000 


15.000 


.500 


82.771 











Table 27-00. Dimensions of Cast-iron Screwed Fittings* 




STANDARD 

A B 

Inches Inches 



EXTRA HEAVY 
A B 



STANDARD AND EXTRA HEAVY 

C D E F 

Inches Inches Inches Inches 



Vs- 
'A- 
H- 

1 . 

l»^. 

2 . 

2^. 

3 . 

ZV2. 

4 . 

4)^. 

5 . 

6 . 

7 . 



9 
10 
12 



1/4 

2M 

2^ 

4^ 

6J^ 

9M 



% 



lA 
lA 
lA 
Hi 

m 

2tV 
2H 

213 
16 

■Jie 

3i% 

Ws 

4M 
4H 

5-3- 
■'16 

6 



2 

214 

2is 

3 

4A 
4ii 

6A 
1H 



9A 
133-^ 



1^ 
IH 
lA 

m 

2M 

2iT 

2H 

3 

3A 

4 

m 



2A 
3 

33^ 

4M 

6H 

VA 

m 
1154 

nA 

13iV 
15J4 

16it 
20H 
20ii 

24,^ 



lA 

2H 
2% 

313 
16 

41^ 

■ 5A 

6A 
1% 

9}^ 
9M 

lOM 

12M 

135^ 
16M 
16M 

19^ 



21f 
3M 
3H 

3^ 
3J^ 
Wi 
4il 

5J^ 

61^ 



2A 

2^ 
2^ 

2^ 
2A 

3^ 
3?^ 
35^ 

4M 



Note — ^The above dimensions are subject to a slight variation. 
*Crane Co. 



27—3 



Table 27-00. Rules for Standard Weight Flanged Fittings 

American 1915 Standard 125-lb. Working Pressure 

Shell Thickness in Inches 




Size Fitting, 


SheU 


Size Fitting, 


SheU 


Size Fitting, 


SheU 


Inches 


Thickness 


Inches 


Thickness 


Inches 


Thickness 


9 


0% 


5 


V2 


12 


% 


iVi 


A 


6 


A 


14 


if 


3 


M 


7 


5^ 


15 


H 


iVi 


y2 


8 


H 


16 


if 


4 




9 


M 


18 


1 


4^ 


Vi 


10 


M 


20 


lA 



1. Standard reducing elbows carry same dimensions center-to-face as regular elbow3 
of largest straight size. 

2. Standard tees, crosses and laterals, reducing on run only, carry same dimensions 
face-to-face as largest straight size. 

3. Where long-turn fittings are specified, it has reference only to elbows which are made 
in two center-to-face dimensions and to be known as "elbows" and "long-turn elbows," 
the latter being used only when so specified. 

4. All standard weight fittings must be guaranteed for 125-lb. working pressure, and 
each must have mark cast on indicating maker and guaranteed working steam pressure. 

5. Standard weight fittings and flanges to be plain faced, and bolt holes to be 3^ in. 
larger in diameter than bolts; bolt holes to straddle center lines. 

6. Size of all fittings scheduled indicates inside diameter of ports. 

7. Square head bolts with hexagonal nuts are generally recommended for use. 

8. Double-branch elbows, side-outlet elbows and side-outlet tees, whether straight or 
reducing, carry same dimensions center-to-face and face-to-face as regular tees and elbows. 

9. Bull-head tees or tees increasing on outlet, will have same center-to-face and face- 
to-face dimensions as a straight fitting of the size of the outlet. 

10. Tees, crosses and laterals 16-in. and smaller, reducing on the outlet, use the same 
dimensions as straight sizes of the larger port. 









Table 27-00. 


Standard Flanges and Bolts 








19 IS standard. 


25-lb. Workine Pressi u-e 




























PIPE 


FLANGE 


BOLTS 


BOLT ] 


aOLES 




-Hi 


'\ 


Size 
P 


Diam. 
D 


Thick- 
ness 
T 


No. 


Size 
Diam. 


Bolt 
Circle 
B. C. 






/^ 




Size 
Diam. 






wx^ 


Ml. 


- 


x] 






8 


131^ 


1^ 


8 


Va 


UH 


Vf^ 








■iy^^-^ 


— - 


— 






9 


15 


1^8 


12 


Va 


13 K 


Vs 
























10 


16 


It^ 


12 


Vi 


14K 


1 


PIPE 


FLANGE 


BOLTS 


BOLT 


HOLES 


12 
14 


19 
21 


Wa 


12 
12 


Vs 
1 


17 
1834 


1 
















IJ^ 


Size 


Diam. 




No. 


Size 


Circle 


Size 


15 


2214 


Wi 


16 


1 


20 


1^ 


P 


D 


T 




Diam. 


B.C. 


Diam. 


16 


23 H 


1t^ 


16 


1 


21 K 


11/8 
















18 


25 


Irk 


16 


li/8 


22% 


IK 
















1 


4 


tV 


4 


tV 


3 


^ 
















IK 


41/, 


y?, 


4 


Ti 


■SH 


16 


20 


21 y. 


lif 


20 


11/8 


25 


IK 


W9. 


5 


TS 


4 


y-?. 


m 


5^8 


22 


2W9. 


lif 


20 


IK 


27 K 


IH 


2 


6 


^8 


4 


^8 


m 


% 


24 


32 


1^8 


20 


IK 


29 K. 


IH 
















26 


3414 


2 


24 


IK 


31^4 


1% 


2 Hi 


7 


H 


4 


^/8 


5^2 


% 
















3 


I'A 


H 


4 


^/8 


6 


% 


28 


36i/« 


2A 


28 


IK 


34 


IVs 


■iy?. 


»y?. 


H 


4 


y^ 


7 


Va 


30 


38 M 


21/s 


28 


IH 


36 


VA 


4 


9 


If 


8 


^8 


-ly?. 


% 


32 


41 M 


2i4 


28 


l'/2 


38 K^ 


IH 
















34 


43^4 


2A 


32 


IK^ 


40 i4 


1^ 


4^ 


914 


if 


8 


y^ 


m 


Vh 
















5 


10 


if 


8 


% 


^y?. 


% 


36 


46 


2^/8 


32 


ly?, 


42% 


IVs 


6 


11 


1 


8 


M 


9'/^ 


% 


38 


48^4 


2?^ 


32 


15/8 


45 K 


VVa 


7 


12 yz 


it^ 


8 


Yi 


10 Nt 


% 


40 


50M 


2^2 


36 


1^8 


474 


IK 



27- 



Sizes 18-in. and larger, reducing on the outlet, are made in two lengths, depending on 
\hr size of the outlet, as given in the table of dimensions. 

11. For fittings reducing on the run only, a long-body pattern will be used. Y's are 
special and made to suit connections. Double-branch elbows aie not made reducing on 
the run. 

L2. Steel flanges, fittings and valves ai'e recommended foi- super-healed steam. 

Ill If flanged fittings for lower working pressure than 125 lb. are made, they shall 
conform in all dimensions, except thickness of shell, to this standard and shall have the 
guaranteed working pressui'e cast on each fitting. Flanges for these fittings must be stand- 
ard dimensions. 



Table 27-00. Standard Flanged Rednring Lateral.'; 
191.") Standard, 12.'i-lb. \\ orliing l^rcssure 




Red cing Lateral 




Reducing-on-Run 
Lateral 




Reducing-on-Run and 
Branch Lateral 



SIZE 
Run 



Branch b 



DIMENSIONS, INCHES 
L M 



FLANGES 
Diam. Thickness 



1 


— 


— 


— 


— 


— 


4 


■h 


IH 


1}4 oi less 


8 


6 14 


IH 


(>% 


W2 


yi 


1^ 


11^ " " 


9 


7 


9 


7 


5 


^ 


2 


2 " " 


lOJ^ 


8 


2J^ 


8 


6 


Vi 


2)-^ 


2H " " 


12 


9K 


2^ 


9M 


7 


H 


i 


3 " " 


13 


10 


3 


10 


7^ 


Va, 


3M 


3}^ ■' " 


14J^ 


iiy2 


3 


\W2 


8J^ 


It 


•I 


4 " " 


15 


12 


3 


12 


9 


nr 


41^ 


m " " 


15J^ 


1214 


3 


12J^ 


9M 


16 


5 


5 " " 


17 


13J^ 


■i'A 


13J^ 


10 


if 


6 


6 " " 


18 


141^ 


W2 


141^ 


11 


1 


7 


7 " " 


20^ 


i6y2 


4 


16^ 


12M 


1t^ 


8 


8 " " 


22 


n'A 


W2 


\iy2 


13J^ 


Wi 


9 


9 " " 


24 


i9y2 


W2 


19J^ 


15 


IH 


10 


10 " " 


25 J^ 


20^ 


5 


20 H 


16 


lA 


12 


12 " " 


30 


241^ 


5H 


24H 


19 


l>4 


14 


14 " " 


33 


27 


6 


27 


21 


Ws 


15 


15 " " 


34 J^ 


28V2 


6 


28'^ 


22M 


W% 


16 


16 " " 


36^ 


30 


63^ 


30 


23M 


li^ 


18 


9 " " 


26 


25 


1 


27}i 


25 


1 9 
Its 


18 


18 to 10 inc. 


39 


32 


7 


32 


25 


1"% 


20 


10 and less 


28 


27 


1 


29}^ 


27^ 


1-i 


20 


20 to 12 inc. 


43 


35 


8 


35 


27}^ 


1-1 


22 


10 and less 


29 


28M 


H 


31 >^. 


29 J^ 


1-1 


22 


22 to 12 inc. 


46 


3TJ^ 


8>^ 


37J^ 


29}^ 


i}i 


24 


12 and less 


32 


31J^ 


y% 


34 J^ 


32 


VA 


24 


24 to 14 inc. 


49 J^ 


40>^ 


9 


40>i 


32 


IK 


26 


12 and less 


35 


35 


• 


38 


34M 


2 


26 


26 to 14 inc. 


53 


44 


9 


44 


34M 


9 


28 


14 and less 


37 


37 





40 


36 1^ 


2tV ■ 


28 


28 to 15 inc. 


56 


46 J^ 


W2 


461^ 


36J^ 


2A 


30 


15 and less 


39 


39 





42 


38Ji 


2% 


30 


30 to 16 inc. 


59 


49 


10 


49 


38M 


2ys 



27- 



Table 27-00. Standard Flanged Ball-Head Rediaing Tees and Crosses 
1915 Standard, 125-Ib. Working Pressure 



J il ' If U^ 



d 



n-p- 



Reducing Tee 



if 



M il l 

Redacing Cross 




Reducing-on-Run Tee 





Reducing-on-Riin and 
Branc Tee Cross 




1^ 
Reducing-on-Run Branch 



SIZE 

Branch *'B" 



A & J 



DIMENSIONS, INCHES 



FLANGES 
Diam. Thickness 



1 


— 


— 


— 








I 


A 


IH 


1 or less 


3M 


33/4 








Wi 


V2 


iVi 


IM " " 


4 


4 








5 


A 


2 


IH " " 


4M 


41^ 








6 


'A 


iVi 


2 " " 


5 


5 








7 


H 


3 


2K " " 


5J^ 


W" 


Note — A reduction in 


size on 


TA 


M 


"iVi 


3 " " 


6 


6 


Ihe run does 


not affect the 


8J4 


il 


4 


iVi " " 


6}^ 


6J4 


dimensions but branch out- 


9 


ii 










lets of small size such 


as are 






4H 


4 " " 


1 


7 


listed below 


will reduce the 


9H ' 


if 


5 


4J^ " " 


W2 


iVi 


dimensions of 


fittings 


18 in. 


10 


if 


6 


5 " " 


8 


8 


or over m size 






11 


1 


1 


6 " " 


8' 2 


8.4 








12J^ 


lA 


8 


7 " " 


9 


9 








13M 


IH 


9 


8 " " 


10 


10 








15 


iVs 


10 


9 " " 


11 


11 








16 


lA 


12 


10 " " 


12 


12 








19 


Hi 


14 


12 " " 


14 


14 








21 


Ws 


15 


14 " " 

15 " " 


14J^ 
15 


14M 
15 


Branch "b" 


J 


K 


22M 
23^ 


Ws 


16 








lA 


18 


18 to 14 inc. 


161^ 


163^ 


12 or less 


13 


15J^ 


25 


Iffe 


20 


20 to 15 inc. 


18 


18 


14 " " 


14 


17 


2iy2 


lii 


22 


22 to 16 inc. 


20* 


20 


15 " " 


14 


18 


29V2 


1x1 


24 


24 to 18 inc. 


22 


22 


16 " " 


15 


19 


32 


VA 


26 


26 to 20 inc. 


23 


23 


18 " " 


16 


20 


34M 


2 


28 


28 to 20 inc. 


24 


24 


18 " " 


16 


21 


36J^ 


2A 


30 


30 to 22 inc. 


25 


25 


20 " " 


18 


23 


38M 


2M 


32 


32 to 22 inc. 


26 


26 


20 " " 


18 


24 


41M 


2M 


34 


34 to 24 inc. 


27 


27 


22 " " 


19 


25 


43M 


2^ 


36 


36 to 26 inc. 


28 


28 


24 " " 


20 


26 


46 


Ws 


38 


38 to 26 inc. 


29 


29 


21 '• '■ 


20 


28 


483^ 


2H 


40 


10 to 28 inc. 


jO 


30 


26 " " 


22 


29 


r^m 


2J^ 



Table 27-00. Standard Flanged Elbows, Crosses, Laterals and Reducers 
1915 Standard, 125-lb. Working Pressure 




Long-Turn Elbow 



Reducing Elbow 



Double-Branch 
Elbow 



< ^A > < A- 



jp^ 



< A >f A — 3 


-: 




l:z---~- 



Straight Tee 




Straight Cross 




Straight Lateral 


Reducer 


SIZE 

Run A 


B 


DIMENSIONS, 
C 


INCHES 
D 


E G 


FLANGE 
Diam. Tliiclmess 



1 


3J^ 


5 


1J€ 


lY, 


5M 


— 


4 


A 


IM 


3M 


5J^ 


2 


8 


6M 


— 


4H 


M 


1^ 


4 


6 


2M 


9 


7 


— 


5 


A 


2 


iii - 


6^ 


2J^ 


\W2 


8 


— 


6 


^ 


2y2 


5 


7 


3 


12 


9J^ 





7 


H 


3 


5H 


7K 


3 


13 


10 


6 


7H 


M 


3)^ 


6 


W% 


3H 


14^ 


IIH 


6Y2 


8M 


M 


4 


6}^ 


9 


4 


15 


12 


7 


9 


if 


4}^ 


7 


W2 


4 


15J^ 


12J^ 


7-^ 


9M 


i5 


5 


W2 


lOM 


4J^ 


17 


13^ 


8 


10 


i| 


6 


8 . 


11 J^ 


5 


18 


\m 


9 


11. 


1 


7 


^Yi 


12M 


5H 


20 J^ 


16Y2 


10 


12H 


llV 


8 


9 


14 


5J^ 


22 


17 J^ 


11 


13}^ 


lYs 


9 


10 


151^ 


6 


24 


19J^ 


11^ 


15 


lYs 


10 


11 


16K 


6J^ 


25 >^ 


2OY2 


12 


16 


lA 


12 


12 


19 


7M 


30 


24,Y2 


14 


19 


IJ^- 


14 


14 


"i-VA 


7)^ 


33 


27 


16 


21 


IVa 


15 


141^ 


22M 


8 


341^ 


28J^ 


17 


22 Ji 


IH 


16 


15 


24 


8 


361^ 


30 


18 


231^ 


lA 


18 


16H 


tf^Yi 


8H 


39 


32 


19 


25 


1^ 


20 


18 


29 


9J^ 


43 


35 


20 


27M 


lii • 


22 


20 


31 J^ 


10 


46 


37)^ 


22 


29 }i 


IM 


24 


22 


34 


11 


49H 


40 J4 


24 


32 


V/b 


26 


23 


36>i 


13 


53 


44 


26 


34Ji 


2 


28 


24 


39 


14 


56 


46 


28 


36^ 


2,^ 


30 


25 


41H 


15 


59 


49 


30 


38M 


2^ 


32 


26 


44 


16 


— 


— 


32 


41 M 


2M 


34 


27 


461^ 


17 


— 


— 


34 


43M 


2A 


36 


28 


49 


18 





^_ 


36 


46 


2H 


38 


29 


51^ 


19 


— 


— 


38 


48?^ 


2H 


40 


30 


54 


20 


' ' 


~ 


40 


50M 


2Y2 



27—7 



Table 27-00. Rules for Extra-Heavy Flanged Fittings 

American 1915 Standard 250-lb. Working Pressure 

Shell Thickness in Inches 




Size Fitting, 


SheU 


Size Fitting, 


SheU 


Size Fitting, 


SheU 


Inches 


Thickness 


Inches 


Thidmess 


Inches 


Thickness 


9 


H 


5 


% 


12 


IVs 


2^ 


Vs 


6 


M 


14 


lA 


3 


Vs 


7 


Vb 


15 


IM 


Wz 


Yb 


8 


H 


16 


lA 


4 


Vs 


9 


1 


18 


lA 


41/2 


16 


10 


li^ 


20 


IVz 



1. Extra heavy reducing elbows carry same dimensions center to face as regular elbows 
of largest straight size. 

2. Extra heavy tees, crosses and laterals, reducing on run only, carry same dimensions 
face-to-face as largest straight size. 

3. Where long turn fittings are specified, it has reference only to elbows which are made 
in two center-to-face dimensions and to be known as elbows and long-turn elbows, the latter 
being used only when so specified. 

4. Extra heavy fittings must be guaranteed for 250-lb. working pressure, and each 
fitting must have some mark cast on it indicating the maker and guaranteed working steam 
pressure. 

5. All extra heavy fittings and flanges to have a raised sm-face ys ™- bigh inside of bolt 
holes for gaskets. Thickness of flanges and center-to-face dimensions of fittings include this 
raised surface. Bolt holes to be J^ in. larger in diameter than bolts. Bolt holes to straddle 
center lines. 



Table 27-00. Extra-Heavy Pipe Flanges and Bolts 
1915 Standard, 250-lb. Working Pressure 







^ 


^T 








PIPE 
Size 


FLANGE 


BOLTS 


BOLT HOLES 




^ - ' 


Diam. 


Thick- 






Bolt 


Bolt 






( 1 (/\ 


7 










ness 


No. 


Size 


Circle 


Hole 






\M 


1- : 


i) 






P 


D 


T 






B.C. 
































8 


15 


1^8 

\Va 


12 


Yb 
1 


13 


1 






' 








9 


I6I4 


12 


14 


Wh 














10 


17 J/2 


Wb 
2 


16 
16 


1 


15M 

17M 


Wb 
Wa 


PIPE 


FLANGE 


BOLTS 


BOLT 


HOLES 


12 


Wb 
















14 


23 


23^ 


20 


Wb 


20M 


1J€ 


Size 


Diam. 


Thick- 


No. 


Size 


Bolt 
Circle 


Bolt 
Hole 


15 


24 J^ 


2A 


20 


Wa 


21 J^ 


Wb 


P 


D 


T 






B.C. 


16 


2bi/s 


2H 


20 


Wa 


22 H, 


Wb 
















18 


281/, 


-IVb 


24 


Wa 


24% 


Wb 
















1 


4J4 


re 


4 


y 


Wa 


Yb 
















V4 


5 


% 


4 


y 


■SVa 


Yb 


20 


30 J^ 


2y. 


24 


Wb 


27 


W?. 


ly?. 


6 


13. 


4 


% 


4^4 


Va 


22 


33 


2Yb 


24 


W. 


29 Ji 


Wb 


2 


by 


% 


4 


Vb 


5 


Ya 


24 


36 


2Va 


24 


Wb 


32 


Wa 
















26 


38M 


2ff 


28 


Wb 


■i^y. 


Wa 


2'/^ 


7y 


1 


4 


Va 


5Vb 


Yb 
















3 


sy 


Wi 


8 


% 


tVB 


Yb 


28 


40M 


2|t 


28 


Wb 


37 


Wa 


3H 


9 


Iffe 


8 


Va 


lyA 


Yb 


30 


43 


3 


28 


Wa 


39 i4 


Wb 


4 


10 


1'4 


8 


Va 


VA 


Yb 


32 


45 i4 


31/R 


28 


Wb 


41'/, 


2 
















34 


^iy. 


3K 


28 


Wb 


431/, 


2 


IVo 


10 H 


lA 


8 


Va 


8H 


Yb 
















5 


11 


1^8 


8 


Va 


9 '4 


Yb 


36 


50 


■iV^ 


32 


Wb 


46 


2 


6 


1-2 y 


lA 


12 


% 


10^^ 


Yb 


38 


52 i4 


3tfe 


32 


Wb 


48 


2 


7 


14 


\y 


12 


Vb 


llKs 


1 


40 


54K2 


3A 


36 


Wb 


50J^ 


2 



27—8 



6. Size of all fittings scheduled indicates inside diameter of ports. 

7. Square head bolts with hexagonal nuts are generally recommended for use. 

8. Double branch elbows, side outlet elbows and side outlet tees, whether straight or 
reducing sizes, carry same dimensions center-to-face and face-to-face as regular tees and 
elbows. 

9. Bull head tees or tees increasing on outlet, will have same center-to-face and face-to- 
face dimensions as a straight fitting of the size of the outlet. 

10. Tees, crosses and laterals 16-in. and smaller, reducing on the outlet, use the same 
dimensions as straight size of the lcu:ger port. Sizes 18 in. and Icu-ger, reducing on the outlet, 
are made in two lengths, depending on the size of the outlet as given in the table of dimen- 
sions. 

11. For fittings reducing on the run only a long body pattern will be used. Y's are 
special and made to suit connections. Double branch elbows are not made reducing on the 
run. 

12. Steel flanges, fittings and valves are recommended for super-heated steam. 



Table 27-00. Extra-Heavy Flanged Reducing Laterals 

1915 Standard, 250-lb. Working Pressure 




Reducing Lateral 




Reducing-on-Run 
Lateral 




Reducing-on-Run and 
Branch Lateral 



SIZE 
Run 



DIMENSIONS, INCHES 
L M 



FLANGES 
Dianu Thickness 



1 


— 


— 


— 


— 


— 


W2 


a 


IH 


\li and less 9)4 


7M 


2M 


7M 


5 


H 


W2 


W2 " 


11 


8V2 


2A 


W2 


6 


a 


2 


2 " 


llj^ 


9 


2A 


9 


6J4 


% 


2^ 


2V2 " 


13 


lOM 


zy2 


lOJ^ 


iy2 


1 


3 


3 


14 


11 


3 


11 


8M. 


, 1% 


3J^ 


3J^ " 


15J^ 


12^ 


3 


12 J^ 


9 


1^ 


4 


4 


WA 


13H 


3 


13M 


10 


134 


4M 


4J^ " 


18 


uy2 


3V2 


\^y2 


lOJ^ 


ij^ 


5 


5 


18J^ 


15 


3)^ 


15 


11 


Ws 


6 


6 


211^ 


17J^ 


4 


17J^ 


i2y2 


li^ 


7 


7 


23J^ 


19 


iVz 


19 


14 


^A 


8 


8 


2SV2 


203^ 


5 


20>^ 


15 


Ws 


9 


9 


2iy2 


22M 


5 


22 Ji 


16M 


IM 


10 


10 


29}4 


24 


5^ 


24 


17J^ 


VA 


12 


12 


33J^ 


27H 


6 


273^ 


20A 


2 


14 


14 


37J^ 


31 


6A 


31 


23 


2A 


15 


15 


39J^ 


33 


6A 


33 


24K 


2A 


16 


16 


42 


34H 


m 


341^ 


25H 


2K 


18 


9 


34 


31 


3 


32 Ji 


28 


ZVs 


18 


16 to 10 inc 


45>^ 


37J^ 


8 


37^ 


28 


2^ 


20 


10 and less 


37 


34 


3 


36 


30H 


2y2 


• 20 


18 to 12 inc 


49 


mA 


8J^ 


40 J^ 


30J^ 


2A 


22 


10 and less 


40 


37 


3 


39 


33 


m 


22 


20 to 12 inc 


53 


43>^ 


9^ 


431^ 


33 


2^ 


24 


12 and less 


44 


41 


3 


43 


36 


2H 


24 


22 to 14 inc 


57J^ 


47J^ 


10 


471^ 


36 


2H 



27—9 



Table 27-00. Extra-Heavy Flanged Bull-Head Reducing Tees and Crosses 

1915 Standard, 250-lb. Working Pressure 



■J— A 




Reducing Tee 



i Ur^rr" 



kr 



k6>l 
Reducing Cross 




Reducing-oa-Run Tee 






BuIUiead Tee 



Reducing-on-Run and Branch Tee 



Reducing-on-Run aud Branch Cross 



SIZE 
Run 



DIMENSIONS, INCHES 
K 



FLANGES 
Diam. Thickness 



1 


— 




— 


— 








4,iA 


i4 


IK 


1 orl 


ess 


4M 


4Ji 








5 


5i 


W2 


IM " 


** 


4}^ 


m 








6 


H 


2 


IM" 


** 


5 


5 








6V2 


Vs 


23^ 


2 " 


" 


5}^ 


5H 








7H 


1 


3 


2^ " 


'* 


6 


6 








83^ 


IH 


^Vi 


3 " 


** 


6}^ 


6J^ 








9 


lA 


4 


3>i " 


" 


7 


7 


Note — A reduction in 


size on 


10 


IM 












the run does 


not affect the 






4^ 


4 " 


" 


7J^ 


7J^ 


dimensions but branch out- 


103-^ 


lA 


5 


4J^ " 


** 


8 


8 


lets of smaller 


size than those 


11 


Ws 


6 


5 " 


" 


.8}^ 


8H 


listed below \¥ill reduce the 


12H 


1t^ 


7 


6 " 




9 


9 


dimensions of 
or over in size 


fittings 


18 in. 


14 


iy2 


8 


7 " 


" 


10 


10 








15 


Ws 


9 


8 " 


" 


lOK 


lOJ^ 








16Ji 


m 


10 


9 " 


** 


11}^ 


11>^ 








1734 


IK 


12 


10 " 




13 


13 








203^ 


2 


14 


12 " 


" 


15 


15 








23 


23^ 


15 


14 " 


" 


15J^ 


15J^ 




T 


K 


24^ 


2A 


16 


15 " 


'* 


leVi 


16>^ 








25M 


234 


18 


18 to 14 


mc. 


18 


18 


12 or less 


14 


17 


28 


2H 


20 


20 to 15 


inc. 


19^ 


193^ 


14 " " 


153^ 


183^ 


303^ 


234 


22 


22 to 16 


inc. 


20^ 


201^ 


15 " " 


1634 


20 


33 


2% 


24 


24 to 18 


mc. 


223^ 


223^ 


16 " " 


17 


2134 


36 


2H 


26 


26 to 20 


mc. 


24 


24 


18 " " 


19 


23 


38Ji 


m 


28 


28 to 20 


inc. 


26 


26 


18 " " 


19 


24 


40 J^ 


211 


30 


30 to 22 


inc. 


27M ■ 


27}^ 


20 " " 


203^ 


2534 


43 


3 


32 


32 to 22 


inc. 


29 


29 


20 " " 


2034 


2634 


453€ 


SVs 


34 


34 to 24 


inc. 


30}^ 


30}i 


22 " " 


22 


28 


47>^ 


SK 


36 


36 to 26 


inc. 


32}^ 


323^ 


24 " " 


2334 


2934 


50 


SVs 


38 


38 to 26 


mc. 


34 


34 


24 " " 


2334 


3034 


52 3€ 


3A 


40 


40 to 28 


mc. 


35K 


353^ 


26 " " 


25 


3134 


5434 


3A 



27—10 



Table 27-00. Extra-Heavy Flanged Elbows, Crosses, Laterals and Reducers 
1915 Standard, 250-Ib. Working Pressure 




Double-Branch 

Elbow 



-^^ 



Straight Tee 



m 



u 



T 



Straight Cross 




Straight Lateral 



-G-H 



SIZE 
Run 



DIMENSIONS, INCHES 
C D 



FLANGE 
Diam. Thickness 



1 


4 


5 


9 


834 


61^ 


— 


434 


H 


IH 


4M 


5}^ 


23^ 


9y2 


TA 


— 


5 


H 


I'A 


4J^ 


6 


2M 


11 


834 


— 


6 


H 


2 


5 


6^ 


3 


1134 


9 


— 


63^ 


y% 


2J^ 


5^ 


7 


3H 


13 


103-4 





7)i 


1 


3 


6 


7M 


33^ 


14 


11 


6 


SH 


134 


3}^ 


63^ 


8M 


4 


15M 


12^ 


6y2 


9 


lA 


4 


7 


9 


m 


1634 


nVi 


7 


10 


l)€ 


41^ 


7H 


93^ 


iH 


18 


14M 


734 


1034 


lA 


5 


8 


lOM 


5 


18)4 


15 


8 


11 


l?4 


6 


8K 


113^ 


5.^ 


2134 


173^ 


9 


i2y2 


lA 


7 


9 


12M 


6 


23^ 


19 


10 


14 


1)^ 


8 


10 


14 


6 


253^ 


20 3-^ 


11 


15 


1^ 


9 


10^ 


15J^ 


63^ 


27)4 


22>i 


11)4 


1634 


IM 


10 


ny2 


163^ 


7 


2934 


24 


12 


17)i 


1J4 


12 


13 


19 


8 


3334 


2734 


14 


. 2034 


2 


14 


15 


213^ 


83^ 


3734 


31 


16 


23 


2^ 


15 


15 H 


22H 


9 


3934 


33 


17 


24H 


2A 


16 


16J^ 


24 


9J^ 


42 


3434 


18 


2514 


2M 


18 


18 


263^ 


10 


4534 


3734 


19 


28 


2^ 


20 


i9y2 


29 


lOH 


49 


40)4 


20 


30)4 


2)4 


22 


■2.W2 


313^ 


11 


53 


4314 


22 


■ 33 


2^ 


24 


22ii 


34 


12 


5714 


4714 


24 


36 


2M 


26 


24 


36^ 


13 






26 


38)^ 


2if 


28 


26 


39 


14 








28 


40M 


2il 


30 


27K 


41}^ 


15 


— 


— 


30 


43 


3 


32 


29 


44 


16 


— 


— 


32 


453^ 


3)i 


34 


30M 


463^ 


17 


— 


— 


34 


47)4 


•3)i 


36 


32M 


49 


18 


. 





36 


50 


3H 


38 


34 


51}^ 


19 


— 


— 


38 


52)4 


3A 


40 


35}^ 


54 


20 


— 


"^ 


40 


54)i 


3i^ 



27—11 



Tabic 27-00. 45-Degrce Offset Connections 





A.^ 


— ■ 






• 


1 


Cen.'re 


Cintre 


Face to 




/.«- /\ - 






1 


Pipe 


to 


to 


Face of 




A. 


k VV i:. 






D 


i 


oi?e 


Cu.H.e 


Fa'c 


45's 


L> 


YV 


/"^ 




y^2K/\.^ 










V 


V/\/^ 






1'-. 


."'■' V 


lil. 


1 ., 


— 32 


JZ 




\ 


yS^'y 


, 




2J--2 




Mi 


/•2 
5-4 


2?< 
3^ 


#t 






■^ \/ 




V 






^ 






3 

4 


5}/s 
6 


2A 

2?^ 
2^ 


^ 
M 

M 


3^ 








3fl 












41^ 


Pipe 


Centre 
to 


Centre 
to 


Face to 
Face of 


Offset 


'IJ^2 




2ii 
3A' 


1 


4^ 
5,^ 


Size 


Centre 


Face 


45's 








A 


B 


C 


D 






















6 


1% 


3i^ 


1 














.lyj 


Yi 


2M 


y% 


Vi 


m 


i 


«■-, 


:!% 


1 


6-// 


% 


21^ 


1 


M 


Iff 


8 


1(1 


! ' > 


1 


T-.S 


1 


2M 


IK 


y^ 


Ifi 












l'4 


3^ 


lA 


K 


2A 













NOTE: Tho Ofl'sfl "n" is . .|ii:il to thn (iislanrn "A" divideil l)y 1.411. 



Table 27-00. Conversion of Mercury and Vapor Pressures 
Inches of Mercury to Pounds per Square Inch 



Tenths 





1 


2 


3 


4 


5 


6 


7 


8 


9 


Inches 


Lb. Sq. In 


Lb. Sq. In. 


Lb. Sq. In. 


Lb. Sq. In. 


Lb. Sq. In. 


Lb. Sq. In. 


Lb. Sq. In. 


Lb. Sq. In. 


Lb. Sq. In. 


Lb. Sq. In. 





0. 


0. 19 


0.98 


1.47 


1.96 


2.46 


2.95 


3.44 


3.93 


4.42 


10 


4.91 


5.40 


5.89 


6.39 


6.88 


7.37 


7.86 


8.35 


8.84 


9.33 


20 


9.82 


10.32 


10.81 


11.30 


11.79 


12.28 


12.77 


13.26 


13.75 


14.24 


30 


14.74 


15.2 


15.7 


16.2 


16.7 


17.2 


17.7 


18.2 


18.7 


19.1 


40 


19.6 


20.1 


20.6 


21.1 


21.6 


22 1 


22.6 


23.1 


23.6 


24.1 


50 


24.6 


25.1 


25.5 


26.0 


26.5 


27.0 


27.5 


28.0 


28.5 


29.0 


60 


29.5 


30.0 


30.5 


.30.9 


31.4 


31.9 


32.4 


32.9 


33.4 


33.9 


70 


.34.4 


.34 9 


35.4 


35.9 


36.3 


36.8 


37.3 


37.8 


38.3 


38.8 


80 


39.3 


39.8 


10.3 


40.8 


41.3 


41.8 


42.2 


42.7 


43.2 


43.7 


90 


44.2 


41.7 


45 2 


45.7 


46.2 


46.7 


47.2 


47.6 


48.1 


48.6 


100 


49.1 


49.6 


.50.1 


.50.6 


51.1 


51.6 


52.1 


52.6 


.53.0 


53.5 









Pounds 


per Square Inch to Inches of Mercury 






Pounds 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Kg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 


In. Hg. 





0. 


2.0352 


4.0704 


6.1056 


8.1408 


10.1760 


12.2112 


14.2464 


16.2816 


18 3168 


10 


20.3.52 


22 . 3872 


24.4224 


26.4576 


28.4928 


30.528 


32.5632 


34.5984 


36.6336 


38.6688 


20 


40.704 


42.7392 


44.7744 


46.8096 


48.8448 


50.8809 


52.9152 


54.9504 


56.9856 


59.0208 


30 


61.056 


63.0912 


65.1264 


67.1616 


69.1968 


71.2320 


73.2672 


75.3024 


77.3376 


79.3728 


40 


81.408 


83.4432 


85.4784 


87.5136 


89.5488 


91.5840 


93.6192 


95.6544 


97.6896 


99.7148 


50 


101.76 


103.795 


105.830 


107.865 


109.900 


111.936 


113.971 


116.006 


118.041 


120.077 


60 


122.11 


124.145 


126.180 


128.215 


130.250 


132.286 


134.321 


136.356 


138.391 


140.427 


70 


142.46 


144.495 


146. 5.30 


148.. 565 


150.600 


152.636 


154.671 


156.706 


158.741 


160.777 


80 


162.81 


164.945 


166.880 


168.915 


170.950 


172 986 


175.021 


177.056 


179.091 


181.127 


90 


183.1-. 


18 i 193 


1C7.230 


189. 2 So 


191,300 


193.33'') 


195 371 


197 405 


199. 141 


201 . !76 


100 


203.53 


205 5fi5 


207.600 


209.635 


211.670 


213.706 


215.711 


217.776 


219 811 


221 816 



27—12 



Table 27-00. Dimensions of Tubular Boilers * 



^ 





















Rate of Evaporation 


Rate of Evaporation 




1 


'S 


1 

II 


£■9 




O ** 


■s 


i 


9 lb. Steam per lb. of Coal 


8 lb. Steam per lb. of Coal 


IS 


2 


P 


¥ 


m o. 




1 




mS. 


1 


a 
1 


1 


Sen 
•3 .3 


i| 

as 
mm 


mmb 


is. 






0) 

m 


•s 

H 
in 


II 


-1 


u5 


■s 

m 


« ft) 

It 


•ao 


30 


28 


2]4 


0.78 


2.8 


20.7 


1.37 


6 


8.5 










24x36 


10x14 


140 


6 
















7 
8 
9 


9.9 
11.2 
12.6 










24x36 
24x36 
24x42 


10x14 
10x14 
10x14 


140 
140 
140 


7 












8 




Use fig 


ures in 


last 


"our 


8 
















10 


14.0 


colum 


ns for 


30- i 


nch 


24x42 


10x14 


140 


8J^ 


36 


34 


2^2 


0.97 


4.0 


25.0 


1.67 


8 

9 

10 

11 
12 


13.6 
15.3 
16.9 
18.6 
20.9 


and 36 


-inch b 


oiler 


s 


30x36 
30x42 
30x42 

30x48 
30x48 


10x16 
10x18 
10x18 

10x20 
10x20 


160 
180 
180 
200 
200 


S'A 












9 












9 












914 


42 


34 


3 


1.44 


5.3 


30.2 


2.0 


9 


18.5 


36x36 


10x20 


i80 


9 


36x42 


10x20 


200 


^Yi 
















10 


20.5 


36x36 


10x20 


180 


93^ 


36x42 


10x20 


200 


9 
















11 


22.5 


36x36 


10x20 


180 


lOM 


36x48 


10x25 


2.50 


9 
















12 


24.5 


36x36 


10x20 


180 


113^ 


36x48 


10x25 


250 


9V^ 
















13 


26.5 


36x42 


10x22 


200 


11 


36x48 


10x25 


250 


10^ 
















14 


28.5 


36x42 


10x22 


200 


12 


36x54 


10x28 


280 


10^ 


48 


44 


3 


1.86 


7.2 


38.4 


2.56 


10 


30.4 


42x36 


10x22 


200 


11 


42x48 


10x28 


280 


9 
















11 


33.2 


42x36 


10x22 


200 


12 


42x48 


10x28 


280 


10 
















12 


35.7 


42x42 


10x25 


220 


11 J^ 


42x54 


10x32 


320 


10 
















13 


38.3 


42x42 


10x25 


220 


12 


42x54 


10x32 


320 


10^ 
















14 


40.8 


42x42 


10x25 


220 


12J4 


42x60 


10x36 


360 


lOM 
















15 


43.4 


42x48 


10x28 


250 


12 


42x60 


10x36 


360 


11 
















16 


45.9 


42x48 


10.x28 


2.50 


12M 


42x60 


10x36 


360 


11 


54 


54 


3 


2.28 


9.3 


46.4 


3.10 


11 


34.6 


48x42 


10x28 


250 


9M 


48x54 


10x38 


380 


8H 
















12 


37.7 


48x42 


10x28 


250 


10 


48x54 


10x38 


380 


9 
















13 


40.8 


48x42 


10x28 


250 


11 


48x54 


10x38 


380 


10 
















14 


43.9 


48x42 


10x28 


250 


12 


48x54 


10x38 


380 


lOJ^ 
















15 


47.0 


48x48 


10x33 


290 


11}^ 


48x60 


10x40 


400 


10 
















16 


50.1 


48x54 


10x38 


320 


12 


48x60 


10x40 


400 


11 




46 


3J^ 


2.67 


8.8 


46.3 


3.10 


17 


53.0 


48x54 


10x38 


320 


12J^ 


48x60 


10x40 


400 


IIJ^ 


60 


72 


3 


3.04 


11.2 


59.6 


4.0 


12 


48.4 


54x48 


10x38 


320 


10 


54x60 


12x40 


460 


W2 
















13 


52.4 


54x48 


10x38 


320 


lOM 


54x60 


12x40 


460 


10 
















14 


56.4 


54x48 


10x38 


320 


12 


54x60 


12x40 


400 


11 
















15 


60.4 


54x54 


12x35 


370 


12 


54x66 


12x42 


500 


lOH 
















16 


64.4 


54x54 


12x35 


370 


12^ 


54x66 


12x42 


500 


u^ 




64 


W2 


3.71 


10.5 


62.4 


4.16 


17 


71.4 


54x60 


12x40 


400 


123^ 


54x72 


12x48 


550 


11 J^ 
















18 


75.6 


54x60 


12x40 


400 


13}^ 


54x72 


12x48 


550 


12 


66 


90 


3 


3.80 


13.5 


74.2 


4.95 


14 


70.1 


60x54 


12x40 


400 


12 


60x66 


12x48 


500 


11 
















15 


75.0 


60x60 


12x44 


450 


12 


60x72 


12x52 


620 


11 
















16 


80.0 


60x60 


12x44 


450 


12M 


60x72 


12x52 


620 


12 




78 


33-^ 


4.52 


12.6 


75.2 


5.10 


17 


86.0 


60x60 


12x44 


450 


13 


66x72 


12x56 


670 


11}^ 
















18 


91.1 


60x60 


12x44 


450 


13J^ 


66x72 


12x56 


670 


12 
















19 


96.2 


60x66 


12x48 


500 


13 


66x72 


12x56 


670 


12J^ 




62 


4 


4.32 


12.4 


69.2 


4.60 


20 


93.1 


60x66 


12x48 


500 


13 


66x72 


12x56 


670 


12 


72 


114 


3 


4.81 


15.7 


92.5 


6.16 


14 


87.4 


66x60 


12x48 


500 


12 


66x72 


12x56 


670 


11^ 
















15 


93.6 


66x60 


12x48 


500 


13 


66x72 


12x56 


670 


12 
















16 


99.7 


66x60 


12x48 


500 


14 


72x72 


12x62 


740 


12 




98 


3M 


5.75 


15.0 


93.0 


6.20 


17 


106.4 


66x66 


12x52 


540 


13J^ 


72x72 


12x62 


740 


13 
















18 


112.6 


66x66 


12x52 


540 


14 


72x72 


12x62 


790 


13 
















19 


118.8 


66x66 


12x52 


540 


li'A 


72x72 


12x62 


790 


14 




72 


4 


5.02 


15.0 


79.7 


5.31 


20 


107.3 


66x60 


12x48 


500 


li'A 


72x72 


12x62 


740 


13 



*HubbEU'd's Steam Power Plants, Second Edition. 

27—13 



Table 27-00. Properties of Saturated Steam 

Reproduced by Permission from Marks and Davis "Steam Tables and Diagrams." Copyright, 1909, by 

Longmans, Green & Co. 



Pressure, Lb. 
Absolute 


Temperature, 
Deg. Fahr. 


Specific Volume, 
Cu. Ft. per Lb. 


Heat of the 
Liquid, B.t.u. 


Latent Heat of 
Evap., B.t.u. 


Total Heat of 
Steam, B.t.u. 


Pressure, Lb. 
Absolute 


1 

2 
3 
4 


101.83 
126.15 
141.52 
153.01 


333.0 

173.5 

118.5 

90.5 


69.8 

94.0 

109.4 

120.9 


1034.6 
1021.0 
1012.3 
1005.7 


1104.4 
1115.0 
1121.6 
1126.5 


1 
2 
3 
4 


5 
6 

7 
8 


162.28 
170.06 
176.85 
182.86 


73.33 
61.89 
53.56 

47.27 


130.1 
137.9 
144.7 
150.8 


1000.3 
995.8 
991.8 
988.2 


1130.5 
1133.7 
1136.5 
1139.0 


5 
6 

7 
8 


9 
10 
11 
12 


188.27 
193.22 
197.75 
201 96 


42.36 
38.38 
35.10 
32.36 


156.2 
161.1 
165.7 
169.9 


985.0 
982.0 
979.2 
976.6 


1141.1 
1143.1 
1144.9 
1146.5 


9 
10 
11 
12 


13 
14 
15 
16 


205.87 
209.55 
213.0 
216.3 


30.03 
28.02 
26.27 
24.79 


173.8 
177.5 
181.0 
184.4 


974.2 
971.9 
969.7 
967.6 


1148.0 
1149.4 
1150.7 
1152.0 


13 
14 
15 
16 


17 
18 
19 

20 


219.4 

222.4 
225.2 
228.0 


23.38 
22.16 
21.07 
20.08 


187.5 
190.5 
193.4 
196.1 


965.6 
963.7 
961.8 
960.0 


1153.1 
1154.2 
1155.2 
1156.2 


17 
18 
19 
20 


22 
24 
26 
28 


233.1 
237.8 
242.2 
246.4 


18.37 
16.93 
15.72 

14.67 


201.3 
206.1 
210.6 
214.8 


956.7 
953.5 
950.6 
947.8 


1158.0 
1159.6 
1161.2 
1162.6 


22 
24 
26 
28 


30 
32 
34 
36 


250.3 
254.1 
257.6 
261.0 


13.74 
12.93 
12.22 
11.58 


218.8 

222.6 
226.2 
229.6 


945.1 

942.5 
940.1 
937.7 


1163.9 
1165.1 
1166.3 
1167.3 


30 
32 
34 
36 


38 
40 

42 
44 


264.2 
267.3 
270.2 
273.1 


11.01 

10.49 

10.02 

9.59 


232.9 
236.1 
239.1 
242.0 


935.5 
933.3 
931.2 
929.2 


1168.4 
1169.4 
1170.3 
1171.2 


38 
40 

42 
44 


46 
48 
50 
52 


275.8 
278.5 
281.0 
283.5 


9.20 
8.84 
8.51 
8.20 


244.8 

247.5 
250.1 
252.6 


927.2 
925.3 
923.5 
921.7 


1172.0 
1172.8 
1173.6 
1174.3 


46 
48 
50 
52 


54 
56 
58 
60 


285.9 

288.2 
290.5 
292.7 


7.91 

7.65 
7.40 
7.17 


255.1 
257.5 
259.8 
262.1 


919.9 
918.2 
916.5 
914.9 


1175.0 
1175.7 
1176.4 
1177.0 


54 
56 
58 
60 


62 
64 
66 
68 


294.9 
297.0 
299.0 
301.0 


6.95 
6.75 
6.56 
6.38 


264.3 
266.4 
268.5 
270.6 


913.3 
911.8 
910.2 
908.7 


1177.6 
1178.2 
1178.8 
1179.3 


62 
64 
66 
68 


70 

72 
74 
76 


302.9 
304.8 
306.7 
308.5 


6.20 
6.04 
5.89 
5.74 


272.6 
274.5 
276.5 
278.3 


907.2 
905.8 
904.4 
903.0 


1179.8 
1180.4 
1180.9 
1181.4 


70 

72 
74 
76 


78 
80 


310.3 
312.0 


5.60 

5.47 


280.2 
282.0 


901.7 
900.3 


1181.8 
1182.3 


78 
80 



27—14 



Table 27-00. Properties of Saturated Steam — Continued 



Pressure, Lb. 
Absolute 


Temperature, 
Deg. Fahr. 


Specific Volume, 
Cu. Ft. per Lb. 


Heat of the 
Liquid, B.t.u. 


Latent Heat of 
Evap., B.t.u. 


Total Heat of 
Steam, B.t.u. 


Pressure, Lb. 
Absolute 


82 
84 
86 
88 


313.8 
315.4 
317.1 
318.7 


5.34 
5.22 
5.10 
5.00 


283.8 
285.5 
287.2 
288.9 


899.0 
897.7 
896.4 
895.2 


1182. 8 
1183.2 
1183.6 
1184.0 


82 
84 
86 
88 


90 
92 
94 
96 


320.3 
321.8 
323.4 
324.9 


4.89 
4.79 
4.69 
4.60 


290.5 
292.1 
293.7 
295.3 


893.9 
892.7 
891.5 
890.3 


1184.4 
1184.8 
1185.2 
1185.6 


90 
92 
94 
96 


98 
100 
105 
110 


326.4 
327.8 
331.4 
334.8 . 


4.51 

4.429 
4.230 
4.047 


296.8 
298.3 
302.0 
305.5 


889.2 
888.0 
885.2 
882.5 


1186.0 
1186.3 
1187.2 
1188.0 


98 

100 
105 
110 


115 
120 
125 
130 


338.1 
341.3 

344.4 
347.4 


3.880 
3.726 
3.583 
3.452 


309.0 
312.3 
315.5 
318.6 


879.8 
877.2 
874.7 
872.3 


1188.8 
1189.6 
1190.3 
1191.0 


115 
120 
125 
130 


135 
140 
145 
150 


350.3 
353.1 
355.8 
358.5 


3.331 
3.219 
3.112 
3.012 


321.7 
324.6 
327.4 
330.2 


869.9 
867.6 
865.4 
863.2 


1191.6 
1192.2 
1192.8 
1193.4 


135 
140 

145 
150 


155 
160 
165 
170 


361.0 
363.6 
366.0 
368.5 


2 920 
2.834 
2.753 
2.675 


332.9 
335.6- 
338.2 
340.7 


861.0 
8.58.8 
8.56.8 
854.7 


1194.0 
1194.5 
1195.0 
1195.4 


155 
160 
165 
170 


175 
180 
185 
190 


370.8 
373.1 
375.4 
377.6 


2.602 
2.533 
2.468 
-2.406 


343.2 
345.6 
348.0 
350.4 


852.7 
850.8 
848.8 
846.9 


1195.9 
1196.4 
1196.8 
1197.3 


175 
180 
185 
190 


195 

200 
205 
210 


379.8 
381.9 
384.0 
386.0 


2.346 
2.290 
2.237 
2.187 


352.7 
354.9 
357.1 
359.2 


845.0 
843.2 
841.4 
839.6 


1197.7 
1198.1 
1198.5 
1198.8 


195 
200. 
205 
210 


215 

220 
225 
230 


388.0 
389.9 
391.9 
393.8 


2.138 
2.091 
2.046 
2.004 


361.4 
363.4 
365.5 
367.5 


837.9 
836.2 
834.4 
832.8 


1199.2 
1199.6 
1199.9 
1200.2 


215 

220 
225 
230 


235 
240 
245 
250 


395.6 
397.4 
399.3 
401.1 


1.964 
1.924 
1.887 
1.850 


369.4 
371.4 
373.3 
375.2 


831.1 
829.5 
827.9 
826.3 


1200.6 
1200.9 
1201.2 
1201.5 


235 
240 
245 
250 



Table 27-00. Horsepower of an Engine 

a = Area of the piston in square inches, p = Mean effective pressure of the steam on the piston per 
square inch, v = Velocity of piston per minute. 

aXpXv 

Then hp.= 

33,000 

The mean pressure in the cylinder when cutting]off at * 

}4 stroke = boiler pressure multiplied by . 597 J^ stroke = boiler pressure multiplied by . 919 

^ " = " " '' " .670 2^ " = " " ^' " .937 

3^ " = " " " " .743 % " = " " " " .966 

1^ " = " " " " .847 % " = " " " " .992 

27—15 









Table 27-00. Properties 


of Air 










VoL 






Elastic 




B.t.u. 


Ab- 


Cu. 


Ft. of 




of Dry 


Cubic 


Weight 


Force 


Feet 


sorbec 


per 


Air Raised 1 


Temper- 


Air 


Feet 


per Cu. 


of 


of 


Cu. Ft. 


of Air 


Deg. Fahr. by 1 


ature, 


with 


per 


Ft. of 


Vapor 


Vapor 


per Deg 


Fahr. 


B.t.a. 


Beg. 


Unity 


Lb. of 


Dry 


In. of 


from 1 










Fahr. 


at 32 


Air 


Ai? 


Mer- 


Lb. of 












Deg. 






cury 


Water 


Dry 


Sat. 


Dry 


Sat. 




Fahr. 










Air 


Air 


Air 


Air 


Zero 


0.935 


11.58 


0.0864 


0.O14 




0.02056 


0.02054 


48.5 


48.7 


12 


0.960 


11.87 


.0.0842 


0.074 




0.02004 


0.02006 


50.1 


50.0 


22 


980 


12.14 


0.0824 


0.118 




0.01961 


0.01963 


51.1 


51.0 


32 


1.000 


12.40 


0.0807 


0.181 


3289 ' 


0.01921 


0.01924 


52.0 


51.8 


42 


1.020 


12.64 


0.0791 


0.267 


2252 


0.01882 


0.01884 


53.2 


52.8 


52 


1.041 


12.88 


0.0776 


0.388 


1595 


0.01847 


0.01848 


54.0 


53.8 


60 


1.057 


12.39 


0.0764 


0.522 


1227 


0.01818 


0.01822 


55.0 


54.6 


62 


1.061 


13.13 


0.0761 


0.556 


1135 


0.01811 


0.01812 


55.2 


54.7 


70 


1.078 


13.34 


0.0750 


0.754 


882 


0.01777 


0.01794 


56.3 


55.5 


72 


1.082 


13.39 


0.0747 


0.785 


819 


0.01767 


0.01790 


56.5 


55.8 


82 


1.102 


13.64 


0.0733 


1.092 


600 


0.01744 


0.01770 


57.2 


56.5 


92 


1.122 


13.90 


0.0720 


1.501 


444 


0.01710 


0.01751 


58.5 


57.1 


100 


1.139 


13.95 


0.0710 


1.929 


356 


0.01690 


0.01735 


59.1 


57.8 


102 


1.143 


14.14 


0.0707 


2.036 


334 


0.01682 


0.01731 


59.5 


57.8 


112 


1.163 


14.40 


0.0694 


2.731 


253 


0.01651 


0.01711 


60.6 


58.5 


122 


1.184 


14.65 


0.0682 


3.621 


194 


0.01623 


0.01691 


61.7 


59.1 


132 


1.204 


14.90 


0.0671 


4.752 


151 


0.01.596 


0.01670 


62.5 


59.9 


142 


1.224 


15.15 


0.0660 


6.165 


118 


0.01571 


0.01652 


63.7 


60.6 


152 


l..';45 


15.40 


0.0619 


7.930 


93.3 


0.01544 


0.01634 


65.0 


61.5 


162 


1.265 


15.65 


0.0638 


10.099 


74.5 


0.01518 


0.01616 


66.2 


g?:4 


172 


1.285 


15.90 


0.0628 


12.758 


59.2 


0.01494 


0.01.598 


67.1 


63.3 


182 


1..S06 


16.17 


0.0618 


15.960 


48.6 


0.01471 


0.01580 


68.0 


64.2 


192 


1.326 


16.42 


0.0609 


19.828 


39.8 


01419 




68.9 




202 


1.347 


16.67 


0.0600 


24.450 


32.7 


01426 




69.5 





212 


1.367 


16.92 


0.0591 


29.921 


27.1 


0.01406 




71.4 





Table 27-00. Volume and Weight of Air at Atmospheric Pressure at 
Temperatures Between 212 and 850 Deg. Fahr. 



Temperature, 


Volume, 


Weight One 


Temperature, 


Volume, 


Weight One 


Weight One 


Volume, 


Temperature, 


D3graes 




Cubic Foot 


Degrees 




Cubic Foot 


Cubic Foot 




Degrees 


Falirenheit 


Cubic Feet 


in Pounds 


Fahrenheit 


Cubic Feet 


in Pounds 


in Poimds 


Cubic Feet 


Fahrenheit 


212 


16.925 


.059084 


320 


19.647 


. 050898 


550 


25.444 


.039302 


220 


17.127 


.058388 


340 


20.151 


. 049625 


575 


26.074 


.038352 


230 


17.379 


. 057541 


360 


20.655 


.048414 


600 


26.704 


.037448 


240 


17.631 


.056718 


380 


21.159 


. 047261 


650 


27.964 


.035760 


250 


17.883 


. 055919 


400 


21.663 


.046162 


700 


29.224 


.034219 


260 


18.135 


.055142 


425 


22.293 


. 044857 


750 


30.484 


.032804 


270 


18.387 


.054386 


450 


22.923 


.043624 


800 


31 . 744 


.031,502 


280 


18.639 


.053651 


475 


23.554 


. 042456 


850 


33.004 


.030299 


290 


18.891 


. 052935 


500 


24.184 


.041350 








300 


19.143 


.052238 


525 


24.814 


. 040300 









27—16 



Table 27-00. Heat Units Per Pound and Weight Per Cubic Foot of Water 
Between 32 Degrees Fahrenheit and 340 Degrees Fahrenheit* 



is 
II 


n § 
Wo. 


51 
Is 

^5 


^1 
II 


11 

Wo. 


Is 

^5 


II 


Wo 


Is 


jl 
6& 


£■0 

3 

eg 

S '■ 

Wo. 


Q0-" 


II 


ll 

w"l 


Is 
^5 


1 

P. <u 

Bfc 


n 

Wo. 


^5 


HO 






HQ 






HO 

108 






HQ 

146 






HP 

184 






HO 

222 






32 


0.00 


62.42 


70 


38.06 


62.30 


75.95 


61.90 


113.86 


61.27 


151.89 


60.49 


190.1 


.59. 58 


33 


1.01 


62.42 


71 


39.06 


62.30 


109 


76.91 


61.88 


147 


114.86j61.25i: 185 


1.52.89 


60.47 


223 


191.1 


.59.55 


34 


2 01 


62.42 


72 


40.05 


62.29 


110 


77.94 


61.86 


148 


115 86 


61 . 24 


186 


153.89 


60.45 


224 


192.1 


.59. 53 


35 


3 02 


62.43 


73 


41.05 


62.28 


111 


78.94 


61.85 


149 


116.86 


61.22 


187 


154.90 


60.42 


225 


193.1 


.59.. 50 


36 


4.03 


62.43 


74 


42.05 


62.27 


112 


79.93 


61.83 


150 


117.86 


61.20 


188 


155.90 


60.40 


226 


194 1 


.59.48 


37 


5.04 


62.43 


75 


43.05 


62.26 


113 


80.93 


61.82 


151 


118 86 


61.18 


189 


156.90 


60.38 


227 


195.2 


59.45 


38 


6.04 


62.43 


76 


44.04 


62.26 


114 


81.93 


61.80 


152 


119 86 


61 . 16 


190 


157. 91160. 36 


228 


196.2 


.59.42 


39 


7.05 


62.43 


77 


45.04 


62.25 


115 


82.92 


61.79 


153 


120.86 


61.14 


191 


1.58.91 


60.33 


229 


197.2 


59.40 


40 


8.05 


62.43 


78 


46.04 


62.24 


116 


83.92 


61.77 


154 


121.86 


61.12 


192 


1.59.91 


60.31 


230 


198.2 


59.37 


41 


9,05 


62.43 


79 


47.04 


62.23 


117 


84.92 


61.75 


155 


122.86 


61 10 


193 


160,91 


60 . 29 


231 


199.2 


59.. 34 


42 


10.06 


62 43 


80 


18 03 


62.22 


118 


85.92 


61.74 


156 


123.86 


61 ()8 


191 


161 92 


60.27 


232 


200.2 


59.32 


43 


11.06 


62.43 


81 


19.03 


62.21 


119 


86.91 


61.72 


157 


124.86 


61.06 


195 


162.92 


60,24 


233 


201.2 


59.29 


44 


12.06 


62.43 


82 


50.03 


62.20 


120 


87.91 


61.71 


158 


125.86 


61.04 


196 


163.92 


60.22 


234 


202.2 


59.27 


45 


13.07 


62.42 


83 


51.02 


62.19 


121 


88.91 


61.69 


159 


126.86 


61.02 


197 


164.93 


60.19 


235 


203.2 


59.24 


46 


14.07 


62.42 


84 


52.02 


62.18 


122 


89.91 


61 68 


160 


127.86 


61.00 


198 


165.93 


60.17 


236 


204.2 


59.21 


47 


15.07 


62.42 


85 


.53.02 


62.17 


123 


90.90 


61.66 


161 


128.86 


60.98 


199 


166.94 


60.15 


237 


205.3 


59.19 


48 


16 07 


62.42 


86 


.54.01 


62.16 


124 


91.90 


61.65 


162 


129.86 


60.96 


200 


167 94 


60.12 


238 


206.3 


59.16 


19 


17.08 


62.42 


87 


55.01 


62.15 


125 


92.90 


61.63 


163 


130.86 


60.94 


201 


168 94 


60.10 


239 


207.3 


59. M 


50 


18.08 


62. 12 


88 


56.01 


62.14 


126 


93.90 


61.61 


164 


131.86 


60.92 


202 


169.95 


60.07 


240 


208.3 


59.11 


51 


19.08 


62.41 


89 


.57.00 


62.13 


127 


94.89 


61.59 


165 


132.86 


60.90 


203 


170.95 


60.05 


241 


209.3 


59.08 


52 


20.08 


62.41 


90 


.58.00 


62.12 


128 


95 89 


61.58 


166 


133.86 


60.88 


204 


171.96 


60.02 


242 


210.3 


59.05 


53 


21.08 


62.41 


91 


59.00 


62.11 


129 


96.89 


61.56 


167 


134.86 


60.86 


205 


172.96 


60.00 


243 


211.4 


59.03 


54 


22 08 


62 . 40 


92 


60 00 


62.09 


130 


97.89 


61.55 


168 


135.86 


60 84 


206 


173.97 


59.98 


244 


212.4 


59.00 


55 


23.08 


62.40 


93 


60.99 


62.08 


131 


98.89 


61.53 


169 


136.86 


60.82 


207 


174.97 


59.95 


245 


213.4 


58.97 


56 


24.08 


62.39 


94 


61.99 


62.07 


132 


99.88 


61.52 


170 


137.87 


60.80 


208 


175.98 


59.93 


246 


214.4 


58.94 


57 


25.08 


62.39 


95 


62.99 


62.06 


133 


100.88 


61.50 


171 


138.87 


60.78 


209 


176.98 


59.90 


247 


215.4 


.58.91 


58 


26.08 


62.38 


96 


63.98 


62.05 


134 


101.88 


61.49 


172 


139.87 


60.76 


210 


177.99 


59.88 


248 


216.4 


58.89 


59 


27.08 


62.37 


97 


6t.98 


62.04 


135 


102.88 


61.47 


173 


140.87 


60.73 


211 


178.99 


59.85 


249 


217.4 


58.86 


60 


28 08 


62 37 


98 65.98 


62.03 


136 


103.88 


61.45 


174 


141 . 87 


60.71 


212 


180 00 


.59 83 


250 


218.5 


58.83 


61 


29.08 


62 36 


99 


66.97 


62.02 


137 


104.87 


61.43 


175 


142.87 


60.69 


213 


181.0 


59.80 


260 


228.6 


.58.55 


62 


30.08 


62.36 


100 


67.97 


62.00 


138 


105.87 


61.41 


176 


143.87 


60.67 


214 


182.0 


59.78 


270 


238.8 


58.26 


63 


31.07 


62.35 


101 


68.97 


61.99 


139 


106.87 


61.40 


177 


144.88 


60.65 


215 


183.0 


59.75 


280 


249.0 


57.96 


64 


32.07 


62.35 


102 


69.96 


61.98 


140 


107 87 


61.38 


178 


145.88 


60.62 


216 


184.0 


59.73 


290 


259.3 


57.65 


65 


33.07 


62.34 


103 


70.96 


61.97 


141 


108.87 


61.36 


179 


146.88 


60.60 


217 


185.0 


59.70 


300 


269.6 


.57.33 


66 


34.07 


62.33 


104 


71.96 


61.95 


142 


109.87 


61.34 


180 


147.88 


60.58 


218 


186.1 


59.68 


310 


279.9 


57.00 


67 


35.07 


62.33 


105 


72.95 


61.94 


143 


110.87 


61.33 


181 


148.88 


60.56 


219 


187.1 


59.65 


320 


290.2 


56.66 


68 


36.07 


62.32 


106 


73.95 


61.93 


144 


111.87 


61.31 


182 


149.89 


60.53 


220 


188.1 


59.63 


330 


300.6 


56.30 


69 


37.06 


62.31 


107 


74.95 


61.91 


145 


112.86 


61.29 


183 


150.89 


60.51 


221 


189.1 


59.60 


340 


311.0 


55.94 



* Steam, Babcock & Wilcox Co. 



-17 



Table 27-00. Weight of Water at Temperatures Used in Physical 
Calculations 



Temperature, Degrees Fahrenheit 



Weight per 

Cubic Foot, 

Pounds 



Weight per 

Cubic Inch, 

Pounds 



At 32 degrees or freezing point at sea level . . . 
At 39.2 degrees or point of maximum density. 

At 62 degrees or standard temperature 

At 212 degrees or boiling point at sea level. . . 



62.418 


03612 


62.427 


0.0.3613 


62.355 


0.03608 


59.846 


0.03469 



Table 27-00. Voluine anrl Weight of DistUled Water at Various 
Temperatures " 



Tem- 
per- 
ature, 
Deg. 

Fahr. 



32 
39.2 
40 
50 

60 
70 
80 
90 

100 
110 
120 
130 

140 
150 



Relative 

Volume 

Water at 39.2 

Deg.= l 



1.000176 
1 . 000000 
1 . 000004 
1.00027 

1 . 00096 
1 . 00201 
1.00338 
1.00504 

1 . 00698 
1.00915 
1.01157 
1.01420 

1.01705 
1.02011 



Weight 
in Lb. 

per 
Cubic 
Foot 


Tem- 
per- 
ature, 
Deg. 

Fahr. 


62.42 


160 


62.43 


170 


62.43 


180 


62.42 


190 


62.37 


200 


62.30 


210 


62.22 


212 


62.11 


220 


62.00 


230 


61.86 


240 


61.71 


250 


61.55 


260 


61.38 


270 


61.20 


280 



Relative 


Weight 


Tem- 


Volume, 

Water at 39.2 

Deg. = l 


per 
Cubic 
Foot 


per- 
ature, 

Deg. 
Fahr. 


1 . 02337 


61 00 


290 


1.02682 


60.80 


300 


1.03017 


60.58 


310 


1.03431 


60.36 


320 


1 . 03835 


60.12 


330 


1.04256 


59.88 


340 


1 . 04343 


59.83 


350 


1.0469 


59.63 


360 


1.0515 


59.37 


370 


1.0562 


59.11 


380 


1.0611 


58.83 


390 


1.0662 


58.. 55 


400 


1.0715 


58.26 


410 


1 . 0771 


57.96 


420 



Relative 
Volume, 
■Waterat39.2 
Deg 



1 . 0830 
1 0890 
l.(;953 
1.1019 

1.1088 
1.1160 
1.1235 
1.1313 

1.1396 
1.1483 
1.1573 
1.167 

1.177 
1.187 



Weight 


Tem- 


Relative 


in Lb. 


per- 


Volume, 


per 


ature, 


Water at 


Cubic 


Deg. 


39.2 Deg. 


Foot 
57.65 


Fahr. 


= 1 


430 


1.197 


57 . 33 


440 


1.208 


.57.00 


450 


1.220 


56.66 


460 


1.232 


.56.. 30 


470 


1 . 244 


55.94 


480 


1.256 


55.57 


490 


1.269 


55.18 


500 


1.283 


.54.78 


510 


1.297 


54.36 


520 


1.312 


53.94 


530 


1.329 


53.5 


540 


1.35 


53.0 


550 


1.37 


52.6 


560 


1.39 



Weight 
in Lb. 

per 
Cubic 
Foot 



52.2 

51.7 
51.2 
50.7 

50.2 
49.7 
49.2 
48.7 

48.1 
47.6 
47.0 
46.3 

45.6 
44.9 



* \larks :ind Davis. (Steam. Babjock & Wilcox Co ) 

Table 27-00. Boiling Point of Water at Various Altitudes 



Boiling Point, 

Degrees 

Fahrenheit 


Altitude Above 

Sea Level, 

Feet 


Atmospheric 

Pressure, 

Pounds per 

Square Inch 


1 

Barometer ; 
Reduced 
to 32 Degrees, 
Inches 


Boiling Point, 

Degrees 

Fahrenheit 


Altitude Above 

Sea Level, 

Feet 


Atmospheric 

Pressure, 

Pounds per 

Square Iiich 


Barometer 

Reduced 

to 32 Degrees, 

Inches 


184 


15221 


8.20 


.16.70 


199 


6843 


11.29 


22.99 


185 


14649 


8.38 


17.06 


200 


6304 


11.52 


23.47 


186 


14075 


8.57 


17.45 


201 


5764 


11.76 


23.95 


187 


13498 


8.76 


17.83 


202 


5225 


12.01 


24.45 


188 


12934 


8.95 


18.22 


203 


4697 


12.26 


24.96 


189 


12367 


9.14 


18.61 


204 


4169 


12.51 


25.48 


190 


11799 


9.34 


19.02 


205 


3642 


12.77 


26.00 


191 


11243 


9.54 


19.43 


206 


3115 


13.03 


26.53 


192 


10685 


9.74 


19.85 


207 


2589 


13.30 


27.08 


193 


10127 


9.95 


20.27 


208 


2063 


13. 57 


27.63 


194 


9579 


10.17 


20.71 


209 


1539 


13.85 


28.19 


195 


9031 


10.39 


21.15 


210 


1025 


14.13 


28.76 


196 


8481 


10.61 


21.60 


211 


512 


14.41 


29.33 


197 


7932 


10.83 


22.05 


212 


Sea Level 


14.70 


29.92 


198 


7381 


11.06 


22.52 











27—18 



Table 27-00. Friction of Water in Pipes 

Giving Velocity in Feet per Second, Friction Head in Feet and Frio! ion Loss in Pounds per Square Inch 

for Each 100 Feet of Pipe Discharging a Given Quantity of Water in Gallons 

per Minute. (Weisbach Formula.) 






(S.9 



■J CO 

a u 

O lU 



" Pipe 







•a 








a 








S 




•s 


»5 


m 




& 


"to 


I 


& 


a^^ 


CS u 


*i 


a^ 






ta 




•^ » 


■s o. 


S <o 










bi.9 


■CJ3 


> 


i.s 



"CO 



r'Pipe 



IH" Pipe 



W 

O i) 
opt, 

fa.S 






IK" Pipe 



2" Pipe 



214" Pipe 



5 
10 
15 
20 

25 
30 
35 
40 

45 
50 
60 
70 

75 i 
80 
90 
100 
125 

150, 
175i 
185! 



3.64 
7.2S 
10.92 
14.56 

18.20 



7.59 
29.90 
66.01 



3.3 
13.0 

28. 7 



115.92 60.4 



6.12 
8.16 



78.0010.20 
12.24 
114.28 
16.32 



1.93 

10.26 
16.05 
28.29 

43.70 
63.25 
85.10 
110.40 



0.84 
3.16 
6.98 
12.30 

19.00 
27.50 
37.00 
48.00 



1.301 0.71 

2.60, 2.41 

3.90 5.47 

5.20, 9.36 

6.5ol 14.72 

7.80 21.04 

9.10 28.52 

10.40, 37.03 



0.31 
1.05 
2.38 
4.07 

6.4 
9.15 
12.4 
16.10 



0.91 
1.82 
2.73 
3.64 



0.27 
1.08 
2.23 
3.81 



4.55 5.02 
5.46 8.62 
6.3711.61 
7.2814.99 



11.70 46.46 20.2 
13.00 57.27 i24.9 
15.6 85.50 37.0 
18.2 114.0 49.3 



19.5 



129.0 



56.1 



8.19 
9.10 
10.92 
12.74 



18.74 
23.00 
32.95 
44.60 



13.6551.52 
14.56 58.45 
16.3881.50 
18.2089.70 



0.12 
0.47 
0.97 
1.66 

2.62 
3.75 
5.05 
6.52 

8.16 
10.00 
14.25 
19.30 

22.4 
25.3 
35.25 
39.0 



0.49 


0.092 


().9K 


0.277 


1.47 


0.577 


2.04 


0.97 


2.60 


1.43 


3. OH 


2.09 


3.64 


2.76 


4.05 


3.68 


4.. 56 


4.60 


5.1(1 


5.61 


6.12 


8.88 


7.14 


11.09 


7.70 


12.23 


8.16 


14.55 


9.1818.02 


10.2 


21.75 


12.80 


34.27 


15.3 


48.76 



0.04 
0.12 
0.25 
0.42 

0.62 
0.91 
1.22 
1.60 

1.99 
2.44 
3.50 
4.80 

5.32 
6.30 
7.80 
9.46 
14.9 

21.2 



0.244 
0.656 
0.985 
1.315 

1.645 
1.97 
2.29 
2.62 

2.95 
3.30 
3.95 
4.60 

4.93 
5.26 
5.91 
6.50 
8.13 

9.80 
11.43 
12.08 



0.046 
0.092 
0.185 
0.323 

0.485 
0.693 
0.92 
1.19 

1.49 
1.86 
2.70 
3.46 

4.14 
4.62 
5.96 
7.36 
11.24 

16.10 
21.75 
24.60 



13.06 28.68 12.47 



0.02 
0.04 
0.08 
0.14 

0.21 
0.30 
0.40 
0.53 

0.66 
0.81 
1.17 
1.50 

1.80 
2.00 
2.58 
3.20 
4.89 

7.00 
9.46 
10.61 



3" Pipe 



3H" Pipe 



4" Pipe 



S" Pipe 



6" Pipe 



7" Pipe 



0.448i 
0.672 
0.896 
1.12 



30 1.345 
35 1.569 
40 1.790 
45j 2.016 

50i 2.24 
60 2.68: 
70 3.136 
75 3.360 



80 
90 
100 
125 

160 
175 
186 
200 

250 
265 
300 



3.684 
4.032 
4.480 
5.60 

5.80 
7.92 
8.34 
9.04 

11.28 
12.40 
13.52 



0.046 
0.092 
0.138 
0.231 

0.30 
0.393 
0.53 
0.64' 

0.80 
1.1.55 
1.385 
1.70 

2.08 
2.64 
3.01 
4.67 

6.55 
8.85 
9.94 
11.54 

17.84 
20.09 
25.76 



0.02 
0.04 
0.06 
0.10 

0.13 
0.17 
0.23 
0.28 

0.35 
0.50 
0.60 
0.75 

0.90 
1.10 
1.31 
1.99 

2.85 
3.85 
4.30 
5.02 

7.76 
8.72 
11.20 



0.498 
0.664 
0.83 


0.046 
0.069 
0.092 


0.996 
1.163 
1.329 
1.494 


0.138 

0.208 

0.254 

. 0.323 


1.66 
1.992 
2.324 
2.490 


0.393 
0.555 
0.879 
0.913 


2.656 
2.988 
3.320 
4.15 


0.948 
1.247 
1.478 
2.219 


4.98 
5.81 
6.14 
6.64 


3.12 
4.208 
4.62 
5.50 


8.30 
8.80 
9.96 


8.55 
9.60 
11.63 



0.02 
0.03 
0.04 

0.06 
0.09 
0.11 
0.14 

0.17 
0.24 
0.38 
0.395 

0.41 
0.66 
0.64 
0.96 

1.35 
1.82 
2.00 
2.38 

3.70 
4.15 
5.04 



1.04 


0.138 


1.17 


0.1615 


1..30 


0.208 


1..56 


0.30 


1.82 


0.439 


1.95 


0.485 


2.08 


0.580 


2.34 


0.60 


2.6(1 


0.763 


3.25 


1.13 


3.80 


1.59 


4.45 


2.146 


4.70 


2.484 


5.1 


2.82 


6.4 


4.37 


6.79 


6.45 


7.60 


6.15 



0.06 
0.07 

0.09 
0.13 
0.19 
0.21 

0.23 
0.26 
0.33 
0.49 

0.69 
0.93 
1.075 
1.22 

1.89 
2.09 
2.66 



0.88 
1.04 
1.20 

1.28 
1.44 
1.60 
2.00 

2.40 
2.80 
2.96 
3.20 

4.00 
4.24 
4.80 



0.1156 
0.162 
0.174 

0.185 
0.208 
0.277 
0.393 

0.578 
0.785 
0.84 
0.972 

1.60 
1.69 
2.15 



0.05 
0.07 
0.075 

0.08 
0.09 
0.12 
0.17 

0.25 
0.34 
0.36 
0.42 

0.65 
0.73 
0.93 



1.14 
1.42 

1.71 
2.00 
2 
2.28 



0.115 
0.161 

0.231 
0.302 
0.36 
0.39 



2.80 0.60 
3.03 0.70 
3.40 0.85 



0.05 
0.07 

0.10 
0.13 
0.156 
0.17 

0.26 

0.303 

0.37 



1.20 
1.38 
1.55 
1.70 

2.10 
2.23 
2.40 



0.093 
0.115 
0.13 
0.162 

0.277 

0.31 

0.393 



0.04 
0.05 
0.056 
0.07 

0.12 

0.134 

0.17 



Hot Water Averages 8 Lb. per Gallon 



27—19 



Table 27-00. Pressures Corresponding to Given Heads of Water in Feet 

Water at maximum density. Temperature, 39.2 deg. fahr. 
h=head in feet. P=pressure in lb. per sq. inch = .443 h. 



H 


P 


H 


P 


H 


P 


H 


P 


H 


P 


H 


P 


H 


P 


1 


.433 


16 


6.928 


31 


13.42 


46 


19.92 


61 


26.41 


76 


32.91 


91 


39.40 


2 


.866 


17 


7.361 


32 


13.86 


47 


20.35 


62 


26.85 


77 


33.34 


92 


39.84 


3 


1.299 


18 


7.794 


33 


14.29 


48 


20.78 


63 


27.28 


78 


33.77 


93 


40.27 


4 


1.732 


19 


8.227 


34 


14.72 


49 


21 22 


64 


27.71 


79 


34.21 


94 


40.70 


5 


2.165 


20 


8.660 


35 


15.15 


50 


21.65 


65 


28.14 


80 


34.64 


95 


41.13 


6 


2.598 


21 


9.09 


36 


15.59 


51 


22.08 


66 


28.158 


81 


35.07 


96 


41.57 


7 


3.031 


99 


9.53 


37 


16.02 


52 


22.52 


67 


29.01 


82 


35.51 


97 


42.00 


8 


3.464 


23 


9.96 


38 


16.45 


53 


22.95 


68 


29.44 


83 


35.94 


98 


42.43 


9 


3.897 


24 


10.39 


39 


16.89 


54 


23.38 


69 


29.88 


84 


36.37 


99 


42.87 


10 


4.330 


25 


10.82 


40 


17.32 


55 


23.81 


70 


30.31 


85 


36.80 


100 


43.30 


11 


4.763 


26 


11.26 


41 


17.75 


56 


24.25 


71 


30.74 


86 


37.24 






12 


5.196 


27 


11.69 


42 


18.19 


57 


24.68 


72 


31.18 


87 


37.67 






13 


5.629 


28 


12.12 


43 


18.62 


58 


25.11 


73 


31.61 


88 


38.10 






14 


6.062 


29 


12.56 


44 


19.05 


59 


25.55 


74 


32.04 


89 


38.54 






15 


6.495 


30 


12.99 


45 


19.48 


60 


25.98 


75 


32.47 


90 


38.97 







Table 27-00. Pressure, in Ounces Per Square Inch Corresponding to 
Various Heads of Water, in Inches* 



Head 
in 


.0 


.1 


.2 


.3 


Decimal parts of an Inch 
.4 .5 


.6 


.7 


.8 


.9 


Inches 
























1 

2 


- '.58 
1.16 


.06 

.63 

1.21 


.12 

.69 

1.27 


.17 

.75 
1.33 


.23 

.81 

1.39 


.29 

.87 

1.44 


.35 

.93 

1.50 


.40 

.98 

1.56 


.46 
1.04 
1.62 


.52 
1.09 
1.67 


3 

4 
5 


1.73 
2.31 
2.89 


1.79 
2.37 
2.94 


1.85 

2.42 
3.00 


1.91 

2.48 
3.06 


1.96 
2.54 
3.12 


2.02 
2.60 
3.18 


2.08 
2.66 
3.24 


2.14 

2.72 
3.29 


2.19 

2.77 
3.35 


2.25 
2.83 
3.41 


6 

7 
8 
9 


3.47 

4.04 
4.62 
5.20 


3.52 
4.10 
4.67 
5.26 


3.58 
4.16 
4.73 
5.31 


3.64 

4.22 
4.79 
5.37 


3.70 
4.28 
4.85 
5.42 


3.75 
4.33 
4.91 
5.48 


3.81 
4.39 
4,97 
5.54 


3.87 
4.45 
5.03 
5.60 


3.92 
4.50 
5.08 
5.66 


3.98 
4.56 
5.14 
5.72 


*Suplee's M. E. Reference Book 


















Table 


27-00. Expansion of Wrought 


-Iron Pipe on the App] 


ication of Heat * 


Temp. Air 

When 

Pipe 

is Fitted 








Increase in Length in Inches per Foot 
When Heated to 








Deg. Fahr. 


160 




ISO 


200 


212 


220 


22S 




240 


274 



32 

50 
70 


.0128 
.0102 
.0088 
.0072 




)144 
3118 
3104 
3088 


.016 
.0134 
.012 
.0104 


.017 
.0144 
.013 
.0114 


.0176 
.015 
.0136 
.012 


.0182 
.0157 
.0142 
.0126 


.0192 
.0166 
.0152 
.0136 


.0219 
.0194 
.0179 
.0163 



Co:— .0000067 per deg. 
27—20 



* Holland Healing Manual. 



Table 27-00. Expansion and Weight of Water from 32 to 500 Deg. Fahr. 



Tem- 
perature 


Relative 
Volume 
by Ex- 
pansion 




Tem- 
perature 


Relative 
Volume 
by Ex- 
pansion 


Weight 

of One 

Cubic 

Foot 


Weight 
of One 
Gallon 


Tem- 
perature 


Relative 
Volume 
by Ex- 
pansion 


Weight 

of One 

Cubic 

Foot 


Weight 
of One 
Gallon 


Deg. 
Fahr. 






Pounds Pounds 


Deg. 
Fahr. 




Pounds Pounds 


Deg. 
Fahr. 




Pounds Pounds 


32 
35 

39.1 
40 


1 


00000 
.99993 
99989 
99989 


62.418 10.0101 
62.422 10.0103 
62.425 10.0112 
62.425 10.0112 


90 

95 

100 

105 


1.00459 
1.00554 
1.00639 
1.007.39 


62.1.33 
62.074 
62.022 
61.960 


9.964 
9.955 
9.947 
9.937 


170 
175 
180 
185 


1.02690 

1.02906 
1.03100 
1.03300 


60.783 
60.665 
60.548 
60.430 


9.748 
9.728 
9.711 
9.691 


45 
46 
50 
!52.3 




99993 
00000 
00015 
00029 


62.422 10.0103 
62.418 10.0101 
62.409 10.0087 
62.400 10.0072 


110 
115 
120 
125 


1.00889 
1.00989 
1.01139 
1.01239 


61.868 
61.807 
61.715 
61.654 


9 922 
9!913 
9.897 
9.887 


190 
195 
200 
205 


1.03500 
1.03700 
1.03889 
1.0414 


60.314 
60.198 
60.081 
59.98 


9.672 
9.654 
9.634 
9.611 


55 

60 
62 
65 




00038 
00074 
00101 
00119 


62.394 10.0063 
62.372 10.0053 
62.355 10.0000 
62.344 9.9982 


130 
135 
140 
145 


1.01390 
1,015.39 
1.01690 
1.01839 


61.563 
61.472 
61.381 
61.291 


9.873 
9.8.59 
9.844 
9.829 


210 
212 
250 
300 


1.0434 
1.0466 
1.06243 
1.09563 


59.82 
59.64 
58.75 
56.97 


9.594 
9.565 
8.422 
9.136 


!0 
75 
80 
85 




00160 
00:39 
00^99 
00379 


62.313 9.9933 
62.275 9 9871 
62.232 9.980 
62.182 9.972 


150 
155 
160 
165 


1.01989 
1 02164 
1.02310 
1.02589 


61.201 
61.096 
60.991 
60.843 


9.815 
9.799 
9.781 
9.757 


400 
500 


1.150.56 
1.22005 


54.25 
51.16 


8.700 
8.204 



Table 27-00. Contents of Round Tanks in U. S. Gallons, for Each Foot in Depth 



Diameter 
Ft. In. 



1 

1 3 

1 6 

1 9 

2 

2 3 

2 6 

2 9 



Gallons, 

1 Foot in 

Depth 



5.8735 

9.1766 

13.2150 

17.9870 

23.4940 
29.7340 
36.7092 
44.4179 

52.8618 
62.0386 
73.1.504 
82.. 5959 

93.97.54 
103.0300 
118.9386 
132.5209 

146.8384 
161.8886 
177.6740 
194.1913 

211.4472 
229.4342 
218.1564 
267.6122 



Diameter Gallons, 

Ft. In. Depth 



7 

7 3 

7 6 

7 9 

8 
8 3 
8 6 
8 9 



11 
11 
11 
11 

12 
12 
12 
12 

13 
13 
13 
13 

14 
14 
14 
14 



287.8032 
308.7270 
830.3859 
352.7665 

375.9062 
399.7666 
424.3625 
449.2118 

710.6977 
743.3686 
776.7746 
810,9143 

848.1890 
881 . 3966 
917.7.395 
954.81.59 

992.6274 
1031.1719 
1070.4514 
1108.0645 

1151.2129 
1192.6940 
1234.9104 
1277.8615 



Diameter 
Ft. In. 



Gallons, 

1 Foot in 

Depth 



15 
15 
15 
15 

16 
16 
16 
16 

17 
17 
17 
17 



21 
21 
21 
21 



22 
22 

22 



18 

18 3 

18 6 

18 9 



1321.5454 
1365.9634 
1407.5165 
1457.0032 

1.503.6250 
1.550.9797 
1599.0696 
1647.8930 

1697.4516 
1747.7431 
1798.7698 
1850.5301 

1903.0254 
19.56.2.537 
2010.2171 
2064.9140 

2590.2290 
2652.2532 
2715.0413 
2778.5486 

2842.7910 
2907.7664 
2973.4889 
3039.9209 



Diameter 
Ft. In. 



23 
23 
23 
23 

24 
24 
24 

24 

25 
25 
25 
25 

26 
26 
26 
26 

27 
27 

27 
27 



28 
28 
28 



Gallons, 

1 Foot in 

Depth 



3107.1001 
3175.0122 
3243.6595 
3313.0403 

3383.1563 
3454.0051 
3525.5929 
3597.9068 

3670.9596 
3744.7452 
3819.2657 
3894.5203 

3970.5098 
4047.2322 
4124.6898 
4202.9610 

4281.8072 
4361.4664 
4441 . 8607 
4522.9886 

4604.8517 
4686.4876 
4770.7787 
4854.8434 



27—21 



Table 27-00. Cost of Water at Stated Rates per 1000 Gallons 



Number 








Cost per 1000 Gallons 








of 
Cubic Feet 


5 Cents 


6 Cents 


8 Cents 


10 Cents 


15 Cents 


20 Cents 


25 Cents 


30 Cents 


20 


10.007 


SO. 009 


$0,012 


$0,015 


$0,021 


$0,030 


$0,037 


$0,045 


10 


0.015 


0.018 


0.024 


0.030 


0.045 


0.060 


0.075 


0.090 


60 


0.022 


0.027 


0.036 


0.015 


0.066 


0.090 


0.112 


0.135 


80 


0.030 


0.036 


0.048 


0.060 


0.090 


0.120 


0.150 


0.180 


100 


0.037 


0.049 


0.060 


0.075 


0.111 


0.1.50 


0.187 


0.224 


2U0 


0.075 


0.090 


• 0,120 


0.150 


225 


0.299 


0.374 


0.449 


300 


0.112 


0.135 


0.180 


0.224 


0.336 


0.419 


0.561 


0.673 


400 


0.150 


0.180 


0.239 


0.299 


0,450 


0.598 


0.748 


0.898 


500 


0.188 


0.224 


0.299 


0.374 


0..564 


0.748 


0.935 


1.122 


600 


0.224 


0.269 


0.3.59 


0.449 


0.448 


0.898 


1.122 


1.346 


700 


0.262 


0.314 


0.419 


0.524 


0,786 


1.047 


1.309 


1.571 


800 


0.299 


0.350 


0.479 


0.598 


0.897 


1.197 


1.496 


1.795 


900 


0.337 


0.404 


0.539 


0.673 


1.011 


1..346 


1.683 


2 020 


1,000 


0.374 


0.449 


0.598 


0.718 


1.122 


1.496 


1.870 


2.244 


2,000 


0.748 


0.898 


1.197 


1.496 


2.244 


2.992 


3.740 


4.488 


3,C00 


1.122 


1.346 


1.795 


2.244 


3.366 


4.488 


5,610 


6.732 


4,000 


1.496 


1.795 


2.393 


2.992 


4,488 


5.984 


7.480 


8.976 


5,000 


1.870 


2.244 


2.992 


3.710 


5.610 


7.480 


9.350 


11.220 


6,000 


2.244 


2.692 


3.590 


4.488 


6.732 


8.976 


11,220 


13.464 


7,000 


2.618 


3.141 


4.189 


5.236 


7.854 


10.472 


13.090 


15.708 


8,000 


2.992 


3.590 


4.787 


5.984 


8.976 


11.968 


14.961 


17.953 


9,000 


3.366 


4.039 


5.385 


6.732 


10.098 


13.464 


16.831 


20.197 


10,000 


3.74 


4.488 


5.984 


7.480 


11.122 


14.961 


18.701 


22.441 


20,000 


7.48 


8,976 


11.968 


14.961 


22.443 


29.992 


37.402 


44.882 


30,000 


11.22 


13.46 


17.95 


22.44 


33.664 


44.88 


56,10 


67.32 


40,000 


14.96 


17.95 


23.94 


29.92 


44.885 


59.84 


74,80 


89.77 


50,000 


18.70 


22.44 


29.92 


37.40 


56.103 


74.80 


93.50 


112.20 


60,000 


22.44 


26.92 


35.90 


44.88 


67.323 


89.76 


112.20 


134.64 


70,000 


26.18 


31.41 


41.89 


52.36 


78.543 


104.72 


130.90 


157.08 


80,000 


29.92 


35.90 


47.87 


59.84 


89.766 


119.68 


149.61 


179. 53 


90,000 


33.66 


40.39 


53.85 


67.32 


100.986 


134.64 


168.. 31 


201.97 


100,000 


37.40 


44.88 


59.84 


74.80 


111.22 


149.61 


187.01 


224.41 


200,000 


74.81 


89.76 


119.68 


149.61 


224.43 


299 22 


374,02 


448.82 


300,000 


112.20 


134.64 


179.53 


224.41 


336.64 


448^83 


561,03 


673.24 


400,000 


149.61 


179.53 


239.37 


299.22 


448.85 


598.44 


748.05 


897.66 


500.000 


187 01 


224.41 


299.22 


374.02 


561.03 


748.05 


935.06 


1122.07 


600,000 


224.41 


269.29 


359.06 


448.83 


673.23 


897.66 


1122.07 


1346.49 


700,000 


261.81 


314.18 


418.90 


523.63 


785.43 


1047.27 


1309.08 


1570.88 


800,000 


299 22 


3.59.05 


478.75 


598.44 


897.66 


1196.88 


1496.10 


1795.32 


9:W,000 


336 '62 


403.94 


538.59 


673.24 


1009.86 


1346.49 


1683.11 


2019.73 


1,000,000 


374.02 


448.83 


598.44 


748.05 


1122.06 


1498.10 


1870.12 


2244.15 


Table 27-00. Water Conversion Factors * 


U. S. gallons 




X 8.33 


= pounds. 


Cubic 


feet of water(39.1°) X 


62.425 


= pounds. 


U. S. gallons 




X 0.13368 =cubicft 


Cubic 


feet of water(39.1°)X 


7.48 


= U.S. gal. 


U. S. gallons 




X231. 00000 =cubicin 


Cubic 


feet of water(39.1°)X 


0.028 


=tons. 


U. S. gallons 




X 3.78 


= liters. 


Pounds of water 


X 


27.72 


= cubic in. 


Cubic inches of water (39.1°) X 0.0360! 


24 = pounds. 


Pound; 


s of water 


X 


0.01602 


= cubic ft. 


Cubic inchej of water (39.1 


°)X 0.0013; 


29=U.S.gal 


Pounds of water 


X 


0.12 


= U.S. gal. 


Cubic inches of water (39.1°) X 0.576381= ounces. 













* American Machinist Hand Book, 

27—22 



Table 27-00. Classification of Coals* 



1 cubic foot of anthracite coal weighs 55 to 66 lb. 
1 " " " bituminous " " 50 to 55 lb. 
1 " " " semi-bituminous coal weighs 48 to 53 lb. 



Name of Coal 



Percentages of Combustible 
Fixed Carbon Volatile Matter 



B.t.u. per Pound 
of Combustible 



Anthracite 97.0 to 92.5 

Semi-Anthracite 92. 5 to 87. 5 

Semi-Bituminous 87. 5 to 75. 

Bituminous, East 75 . to 60 . 

West 65.0 to 50.0 

Lignite 50 . and under 



S.Oto 7.5 
7.5 to 12.5 
12.5 to 25.0 
25.0 to 40.0 
35.0 to 50.0 
50 . and over 



14,600 to 14,800 
14,700 to 15,500 
15,500 to 16,000 
14,800 to 15,300 
13,500 to 14,800 
11,000 to 13,500 



* Harding and Willard. 

Table 27-00. Names and Sizes of Bituminous or "Soft" Coal* 

For " Domestic" soft coals there are no uniform names and sizes, but they are marketed in the various 
states under about these classes: 

"Screenings" usually smallest sizes. 

"Duff" goes through J/s-inch screen. 

"No. 3 Nut" goes through l}^-in. screen, over J^-inch screen. 

"No. 2 Nut" goes through 2-inch screen, over IM-inch screen. 

"No. 1 Domestic Nut" goes through 3-inch screen, over 1}^- or 2-inch screen. 

"No. 4 Washed" goes through ^-inch screen, over J^-inch screen. 

"No. 3 Washed Chestnut" goes through l}^-inch screen, over J^-inch screen. 

"No. 2 Washed Stt)ve" goes through 2-inch screen, over IM-inch screen. 

"No. 1 \\ Mshcd I'.gg" goes through 3-inch screen, over 2-inch screen. 

"No. 3 Roller Screened Nut" goes through IJ^-inch screen, over 1-lnch screen. 

"No. 2 Roller Screened Nut" goes through 2-inch screen, over IJ^-inch screen. 

"No. 1 Roller Screened Nut" goes through 3J^-inch screen, over 2-inch screen. 

"Egg" goes through 6-inch, over 3-inch screen. 

"Lump" or "Block" goes through 6-inch screen, or over. 

"Run-of-Mine" in fine and large lumps. 

Pocahontas Smokeless: generciUy sized £is: "Nut," "ISgg," "Lump," and "Mine-Run." 

♦Hording and Willard. 

Table 27-00. Heat Values of Bituminous Coals* 
From selected free-burning and caking soft fuels taken from U. S. Geological SarveY Bulletin No. 332, and 

U. S. Bureau of Mines Bulletm No. 23 



Test 
No. 



Kind of Fuel 



County 



B.t.u. 
per Lb. 
Dry Coal 



Alabama 375 

Alabama 484 

Arkansas 293 

Arkansas 308 

Arkansas 340 

Georgia 481 

Illinois 448 

Illinois 511 

lUinois 509 

Indiana 428 

Indiana 435 

Indiana 464 

Indian Territory 437 

Indian Territory 449 

Kansas 311 

Kentucky 434 



Soft— caking. . Bibb 13,671 

Soft — free burning Jefferson 14,447 

Soft — caking Sebastian 13,705 

Semi-anthracite — caking Johnson 14,125 

Lignite Quachita 9,549 

Soft — free burning Chattooga 12,865 

Soft — free burning Williamson 12,920 

Soft briquettes St. Clair 13,271 

Soft — caking Sgiline 13,621 

Soft — ^free burning Greene 13,099 

Soft — caking Pike 13,545 

Soft briquettes Parke 11,930 

Soft — ^free burning 13,932 

Semi-anthracite 14,682 

Soft — free burning Linn. . 12,343 

Soft — free burning Union 14,026 



* Harding and Willard. 

27—23 



Table 27-00. Heat Values of Bituminoug Coals* — Continued 

From selected free-burning and caking soft fuels taken from U. S. Geological Survey Bulletin No. 332, and 
U. S. Bureau of Mines Bulletin No. 23 



Test 
No. 



County 



B.t.u. 

per Lb. 
Dry Coal 



Maryland 490 

M iryland 518 

Missouri 319 

Montana 477 

New Mexico 392 

New Mexico 387 

Ohio ._ 483 

Pennsylvania 473 

Pennsylvania 499 

Pennsylvania 514 

Tennessee 409 

Tennessee 368 

Tennessee 363 

Texas 291 

Utah 404 

Virginia 482 

Virginia 507 

Washington 290 

WasMngton 359 

West Virginia. 305 

West Virginia 439 

Wyoming 399 

Wyoming 400 



Soft — free burning Allegany 14,515 

Soft briquettes Allegany 14,717 

Soft — caking Randolph 11,747 

Lignite — free burning Carbon 11,628 

Soft— caking Colfax 13,059 

Soft— free burning Colfax 12,721 

Soft — free burning Belmont 13,381 

Soft— caking Indiana 14,240 

Soft — free burning Cambria 14,119 

Soft briquettes Westmoreland 14,382 

Soft briquettes Claiborne 14,092 

Soft — free burning Campbell 14,008 

Soft — caking Grundy 13,257 

Lignite — free burning Wood 11,131 

Soft — free burning Summit 12,586 

Anthracite — free bm-ning Montgomery 12,679 

Soft— caking Tazewell 14,177 

Subbit — free burning King 11,772 

Soft— free burning Kittitas 12,996 

Soft — free burning Marion 13,964 

Soft — caking Kanawha 13,995 

Soft — free burning Carbon 12,222 

Subbit — free burning Unita 12,488 



Note — ^These values were obtained at the St. Louis Testing Plant from 139 samples of coed. The 
heating values of the various coals were established by " actually burning one gram of the air-dried coal in 
oxygen in a Mahler-bomb calorimeter." These values in B.t.u. give the theoretical maximum thermal 
value of soft coals. 



♦Harding & Willard. 



Table 27-00. Names and Sizes of Anthracite or "Hard" Coal* 



Names of Sizes 



Will Pass Through 



Will Not Pass Through 



Buckwheat No. 1 \ 

No. 2 / 

or Rice 

Pea 

Chestnut, or Nut 

Stove or Range 

Egg — in the East 

Large Egg — Chicago 

Small Egg — Chicago 

Broken, or Grate 



J^-in. mesh 


M-in. mesh 


M-in. mesh 


J^-in. mesh 


J^-in. mesh 


H-in. mesh 


IM-in. mesh 


Ji-in. mesh 


1^-in. mesh 


l}4-in. mesh 


2J^-in. mesh 


IM-in. mesh 


4 -in. mesh 


2J^-in. mesh 


2J^-in. mesh 


2 -in. mesh 


4 -in. mesh 


2J^-in. mesh 



♦Harding and Willard. 



27—24 



Table 27-00. Composition and Heat Values of Anthracite Coals* 



Locality 



Fixed 
Car- 
boa 



Vola- 
tile 



Mois- 
ture 



Sul- 
phur 



B.t.u. 

per Lb. 

of Dry 

Coal 



Anthracite 

Pennsylvania 78. 60 

Buckwheat 81.32 

Wilkesbarre 76. 94 

Scranton 79. 23 

Scranton 84. 46 

Cross Creek 89. 19 

Lehigh Valley 75.20 

Lykens Valley 76. 94 

Lykens Valley 81 . 00 

Wharton 86. 40 

Buck Mt 82. 66 

Beaver Meadow 88.94 

Lackawanna 87. 74 

Rhode Island 85.00 

Arkansas 74.49 

Semi- Anthracite 

Pennsylvania, Loyalsock 83 . 34 

Bernice 82.52 

Bernice 89. 39 

Wilkes-Barre 88.90 

Lycoming Creek 71 . 53 

Virginia, Natural Coke 75. 08 

Arkansas 74. 06 

Indian Territory 73 . 21 

Maryland, Easby 83.60 







14.80 


0.40 




3.84 


3.88 


10.96 


0.67 


12,200 


6.42 


1.34 


15.30 


.... 


11,801 


3,73 


3.33 


13.70 


.... 


12,149 


5.37 


0.97 


9.20 


.... 


12,294 


1.96 


3.62 


5.23 





13,723 


7.36 


1.44 


16.00 




12,423 


6.21 


.... 


.... 


. . * • 


15,300 


5.00 








15,300 


3.08 


3.7i 


6.22 


6.58 


15,000 


3.95 


3.04 


9.88 


0.46 


15,070 


2.38 


1.50 


7.11 


0.01 




3.91 


2.12 


6. 35 
7.00 


0.12 
0.90 




14.73 


i.52 


9.26 


.... 


13,217 


8.10 


1.30 


6.23 


1.03 


15,400 


3.56 


0.96 


3.27 


0.24 


15,050 


8.56 


0.97 


9.34 


1.04 


15,475 


7.68 




3.49 


.... 


14,199 


13.84 


6.67 


13.96 


0.03 




12.44 


1.12 


11.38 


0.47 




14.93 


1.35 


9.66 






13.65 


5.11 


8.03 


i.is 


13,662 


16.40 






— 


11,207 



*Harding & Willard 



Table 27-00. Weight of Materials 
Dry Woods 



Weight in 
Material Lb. of One 

Cu. Ft. 

Ash 43-53 

Be;ch 43-53 

Birch 40-46 

Boxwood 57-83 

Cork 15 

Ebony 70-83 

Elm 34^45 



Weight in 
Material Lb. of One 

Cu. Ft. 

Fir, Spruce 30-44 

Greenheart 70 

Hornbeam 47 

Larch 31-37 

Lignum- vitae 83 

Mahogany — Honduras. 35 

" Spanish. ... 53 



Material 



Weight in 

Lb. of One 

Cu. Ft. 



Oak — American red. ... 54 

" EngUsh 48-58 

Pine— red 30-44 

white 27-34 

yellow 29-41 

Teak 41-55 



Stones,"Earth,^tc. 



Weight in 
Material Lb. of One 

Cu. Ft. 

Asphaltum 64-112 

Brick — common 100-125 

fire 137-150 

Cement— Portland 80-90 

Clay 120 

Concrete 120-140 

Earth 77-120 

Glass — crown 156 



Weight in 
Material Lb. of One 

Cu. Ft. 

Glass— flint 187 

plate 169 

Granite 164—175 

Gravel 90-125 

Grindstone 134 

Lime — quick 52 

Limestone and marbles . 150-179 

Mortar— hardened 88-118 



Weight in 
Material Lb. of One 

Cu. Ft. 

Mud — dry and close .. . 80-110 
wet and fluid . . . 104-120 

Sand— dry 88-110 

wet 118-129 

Sandstone 130-170 

Victoria stone (crushed 
granite. Portland ]■ 144 
cement, silica) .... 



27—25 



Table 27-00. Weight of Materials— Continued 

Metals and Alloys 



MATERIAL 



Specific 
Gravity 



Weiglit in Lb 




of One 




Cu. Ft. 


Cu. In. 


160 


.093 


167 


.097 


485 


.281 


418 


.242 


358 


.207 


612 


.354 


490 


.284 


525 


.304 


505 


.292 


512 


.296 


530 


.307 


527 


.305 


533 


.308 


528 


.306 


552 


.319 


544 


.315 


537 


.311 


556 


.■322 


549 


.318 


554 


.321 


1203 


.696 


1090 


.631 


430 


.249 


499 


.266 


464 


.260 


470 


.272 


486 


.281 


480 


.278 


708 


.410 


712 


.412 


499 


.289 


516 


.299 


541 


.313 


1340 


.775 


655 


.379 


487 


.282 


493 


.285 


490 


.284 


462 


.267 


456 


.264 


428 


.248 


449 


.260 



Cu. In. 

in One 

Lb. 



Aluminum — cast 

" wrought. 

." bronze... 

Antimony 

Arsenic 



Bismuth ... 
Brass — cast . 



Muntz — metal . 
naval (rolled). 



from 

to 

average 



sheet . 
wire. . 



Bronze (gun-metal). 



Copper — cast 

" hammered . 



[from 
Atq 
[average 



" sheet '. . . . . 

" wire 

Gold (pure) 

" standard 22 carat fine. 



(Gold 11— Copper 1) 

{from 
to 
average 
(from 
to 
average 

Lead — cast 

" sheet 

Manganese 

Nickel — cast . . . .' 

rolled 

Platinum 

Silver 

[from 
Steel Ho 

[average 

Tin 

White Metal (Babbitt's) 

Zinc — cast 

" sheet 



2.569 
2.681 
7.787 
6.712 
5.748 

9.827 
7.868 
8.430 
8.109 
8.221 
8.510 

8.462 
8.558 
8.478 
8.863 
8.735 
8.622 
8.927 

8.815 

8.895 

19.316 

17.502 



6.904 
7.386 
7.209 

7.547 
7.803 
7.707 

11.368 

11.432 

8.012 

8.285 

8.687 

21:516 

10.517 

7.820 

7.916 

7.868 



418 

322 
872 
209 



10.80 

10.35 

3.56 

4.13 

4.83 

2.82 
3.53 
3.29 
3.42 
3.37 
3.26 

3.28 
3.24 
3.27 
3.13 
3.18 
3.22 
3.11 

3.15 
3.12 
1.44 
1.59 



4.02 
3.76 
3.85 
3.56 
3.68 
3.60 

2.44 
2.43 
3.46 
3.35 
3.19 

1.29 
2.64 
3.55 
3.51 
3.53 

3.74 
3.79 
4.04 
3.85 



Table 27-00. Specific Heat and Densities of Building Materials! 



Building Materials 



Specific 
Heat 



Brickwork 0.1950 

Masonry 2159 

Plaster 2000 

Pinewood 4670 



Building Materials 



Specific 
Heat 



Oakwood 0.5700 

Birch 4800 

Glass 1977 



Densities 



Lb. 
per 1 
Cu. Ft. 



Stonework 160 

Wood 40 

Slate 170 

Plaster ; . . 90 



t Harding and WiUard. 

27—26 



Table 27-00. Specific Heats of Various Substances 



Solids 



Temperature,^ 

Degrees 

Falirenheit 

Copper 59-460 

Gold 32-212 

Wrought iron 59-212 

Cast Iron 68-212 

Steel (soft) 68-208 

Steel (hard) 68-208 

Zinc 32-212 

Brass (yellow) 32 



Specific 
Heat 

0.0951 
.0316 
.1152 
.1189 
.1175 
.1165 
.09.35 
.0883 



Temperature,* 

Degrees Specific 

Fahrenheit Heat 

Glass (normal ther. 16'") .... 66-212 0. 1988 

Lead 59 .0299 

Platinum ; 32-212 . 0323 

Silver 32-212 .0559 

Tin 105-64 . 0518 

Ice . 5040 

Sulplmr (newly fused) .2025 



Li:iuids 



Te'B.P"?*":^'* Specific 
Degrees "i, 

Fahrenheit ^"^^ 



Water. . . , 
Alcohol . 
Mercury. 
Benzol . . 



Glycerine 

Lead (melted). 



59 


1.0000 


(32 
1176 


0.5475 


. 7694 


32 


.3346 


/SO 


.4066 


\122 


.4502 


.59-102 




to 360 


.0410 



Temperature,* o-p^jfi^ 

Degrees ^'"'f 

Fahrenheit ^^^^ 

Sulphur (melted) 246-297 . 2350 

Tin (meltedl . 637 

Sea-water (sp.gr. 1.0043) .... 64 .980 

Sea-water (sp.gr. 1.0463) .... 64 . 903 

Oil of turpentine 32 .411 

Petroleum 64-2] 198 

Sulphuric acid 68-133 . 3363 

Olive oil .309 



Gases 



Air 

Oxygen . . . 
Nitrogen . . 
Hydrogen . 



Tempera- 
ture,^- 
Degrees 
Fahrenheit 

32-392 
5.5-405 
32-392 
54-388 



Specific 
Heat at 
Constant 
Pressure 

0.2375 
.2175 
.2438 

3.4090 



Specific 
Heat at 
Constant 
Volume 

0.1693 
.1553 
.1729 

2.4141 



Tempera- Specific Specific 

ture,^- Heat at Heat at 

Degrees Constant Constant 

Fahrenheit Pressure Volume 

Carbon monoxide. .. . 41-208 0.2425 0.1728 

Carbon dioxide 52-417 .2169 .1535 

Methane 64-406 . 5929 . 4505 

Blast-Fur. gas (approx.) 2277 

Flue gas (approx.) 2400 



* When one temperature alone is given the "true" soecific heat is given; otherwise the value is the "mean" specific heat for the 
range of temperature given. 



Table 27-00. TensUe Strength of Materials 

Average Value in Pounds per Square Inch 



Antimony 1053 

Aluminum — castings 15000 

sheet 24000 

bars 28000 

Brass— yellow 26880 

Bronze— cast 34000 

delta metal— cast 44800 
" roUed 67200 

gun metal 32000 

phosphor 40000 

" manganese 62720 

Tobin 78500 

Copper— cast 22400 

sheet 30240 

wire 40000 

Cast Steel 80000 



Gold 20384 

Iron — cast 25000 

" 18000 

wrought 45000 

Lead — cast 1800 

rolled sheet 3320 

Platinum wire 53000 

"Puddled" Semi-steel 

35000 to 42000 

Silver— cast 40000 

Steel— cast 60000 to 80000 

forgings. . . 60000 to 95000 

Tin— cast 3360 

Zinc— cast 3360 

sheet 15680 



Woods 

Ash 11000 to 

Beech 11500 to 

Cedar 10300 to 

Chestnut 10500 

Elm 13000 to 

Hemlock 8700 

Hickory 12800 to 

Locust 20.500 to 

Maple 10500 to 

Oak— white 10253 to 

Pine— white 10000 to 

yellow 12600 to 

Spruce 10000 to 

Walnut-black.... 9286 to 



17000 
18000 
11400 

13489 

18000 
24800 
10584 
19500 
12000 
19200 
19500 
16000 



27—27 



Table 27-00. Lineal Expansion of Solids at Ordinary Temperatures 

(Tabular Values Represent Increase per Foot per 100 Degrees Increase 
in Temperature, Fahrenheit or Centigrade) 



Temperature 

Conditions* 
Degrees Fahrenheit 



CuefGcient per 100 
Degrees Fahrenheit 



Coefficient per 100 
Degrees Centigrade 



Brass (cast) 

Brass (wire) 

Copper 

Glass (English flint) 

Glass (French flint) 

Gold 

Granite (average) 

Iron (cast) 

Iron (soft forged) 

Iron (wire) 

Lead 

Mercury 

Platinum 

Limestone 

Silver 

Steel (Bessemer rolled, hard) 

Steel (Bessemer rolled, soft) 

Steel (cast, French) 

Steel (cast annealed, English) 

*Where rangi" of ti^mperalure Ls given, 
tCopflicienl of rubii-.al exjtansioa. 



32 to 212 
32 to 212 
32 to 212 
32 to 212 

32 to 212 

32 to 212 

32 to 212 

104 

to 212 
32 to 212 
32 to 212 
32 to 212 

104 
32 to 212 

104 
to 212 

to 212 
104 
104 



.001042 
.001072 
. 000926 
. 000451 

.000484 
. 000816 
. 000482 
. 000589 

. 000634 
. 000800 
. 001505 
. 009984t 

.000499 
.000139 
. 001067 
.00056 

.00063 
. 000734 
. 000608 



.001875 
.001930 
.001666 
.000812 

.000872 
.001470 
. 000868 
.001061 

.001141 
.001440 
. 002709 
.017971t 

. 000899 

. 000251 

. 001921 

.00101 

.00117 
.001322 
. 001095 



efficient is mean over range. 









Table 


27-00. D 


ecimal Equivalents of Fractions of 


an Inch 






Fractions 


Decimals 


Fractions 


^Decimals 


Fractions 


Decimals 


^ 


^ 






.015625 
.03125 


II 






H 


.359375 
.375 


44 


¥f 






.703125 
.71875 


^i 








.046875 


*^ 








.390625 


n 








.734375 








^ 




.0625 




32 






.40625 








% 


.75 


A 


> 








.078125 
.09375 


2J. 
64 




Ts 




.421875 
.4375 


49 
64 


i* 






.765625 
.78125 


A 








H 


.109375 
.125 


If 


M 






.453125 
.46875 


a 




16 




.796875 
.8125 


A 


> 








.140625 
.15625 


3A 
64 






y? 


.484375 
.5 


64 


'4 






.828125 
.84375 


a 






16 




.171875 
.1875 


M 


U 






.515625 
.53125 


If 






Vs 


.859375 
.875 


M 










.203125 
.21875 


35 
64 




^ 




.546875 
.5625 


H 


u 


•• 


■■ 


.890625 
.90625 


l_5 
64 


' 






H 


.234375 
.25 


u 


U 






.578125 
.59375 


59 
64 




ii 




.921875 
.9375 


a 


9 








.265625 
.28125 


if 


■■ 




Vh 


.609375 
.625 


If 


fi 




■■ 


.953125 
.96875 


a 






16" 




.296875 
.3125 


a 


fi 






.640625 
.65625 


M 






1 


.984375 
1.00 


■ V- 


a 






.328125 
.34375 


u 




ii 

16 




.671875 
.6875 













27—28 



Table 27-00. Decimals of a Foot for Inches and Fractions of an Inch 

Inch 0" 1" 2" 3" 4" S" 6" 7" 8" 9" 10" 11" 

.0833 .1667 .2500 .3333 .4167 .5000 ..5833 .6667 .7.500 .8333 .9167 

^ .0026 .0859 .1693 .2526 .3359 .4193 .5026 .5859 .6693 .7526 .83.59 .9193 

^ .0052 .0885 .1719 .2552 .3385 .4219 .5052 .5885 .6719 .75.52 .8385 .9219 

h .0078 .0911 .1745 .2578 .3411 .4245 .5078 .5911 .6745 .7578 .8411 .9245 

yi .0104 .0937 .1771 .2604 .3437 .4271 .5104 .5937 .6771 .7604 .8437 .9271 

^ .0130 .0964 .1797 .2630 .3464 .4297 .5130 .5964 .6797 .7630 .8464 .9297 

^ .0156 .0990 .1823 .2656 .3490 .4323 .5156 .5990 .6823 .7656 .8490 .9323 

A .0182 .1016 .1849 .2682 .3516 .4349 .5182 .6016 .6849 .7682 .8516 .9349 

14 .0208 .1042 .1875 .2708 .3542 .4375 .5208 .6042 .6875 .7708 .8542 .9375 

A .0234 .1068 .1901 .2734 .3568 .4401 .5234 .6068 .6901 .7734 .8.568 .9401 

^ .0260 .1094 .1927 .2760 .3594 .4427 .5260 .6094 .6927 .7760 .8594 .9427 

^ .0286 .1120 .1953 .2786 .3620 .4453 .5286 .6120 .6953 .7786 .8620 .9453 

% .0312 .1146 .1979 .2812 .3646 .4479 .5312 .6146 .6979 .7812 .8646 .9479 

a .0339 .1172 .2005 .2839 .3672 .4505 .5339 .6172 .7005 .7839 .8672 .9505 

^ .0365 .1198 .:031 .2865 .3698 .4531 .5365 .6198 .7031 .7865 .8f98 .9531 

M .0391 .1224 .2057 .2891 .3724 .4557 .5391 .6224 .7057 .7891 .8724 .9557 

}4 .0-117 .1250 .2083 .2917 .3750 .4583 .5417 .6250 .7083 .7917 .8750 .9583 

i, .0443 .1276 .2109 .2943 .3776 .4609 .5443 .6276 .7109 .7943 .8776 .9609 

^ .0469 .1302 .2135 .2969 .3802 .4635 .5469 .6302 .7135 .7969 .8802 .9635 

M .0495 .1328 .2161 .2995 .3828 .4661 .5495 .6328 .7161 .7995 .8828 .9661 

yg .0.521 .1354 .2188 .3021 .3854 .4688 .5521 .6354 .7188 .8021 .88.54 .9688 

f* .0.547 .1380 .2214 .3047 .3880 .4714 .5547 .6.380 .7214 .8047 .8880 .9714 

fi .0573 .1406 .2240 .3073 .3906 .4740 .5573 ,6406 .7240 .8073 .8906 .9740 

a .0599 .1432 .2266 .3099 .3932 .4766 .5599^ .6432 .7266 .8099 .8932 .9766 

M -0625 .1458 .2292 .3125 .3958 .4792 .5625 .6458 .7292 .8125 .8958 .9792 

If .0651 .1484 .2318 .3151 .3984 .4818 ,5651 .6484 .7318 .8151 .8984 .9818 

i| .0677 .1510 .2344 .3177 .4010 .4844 .5677 .6510 .7344 .8177 .9010 .9844 

a .0703 .1536 .2370 .3203 .4036 .4870 .5703 .6536 .7370 .8203 .9036 .9870 

% .0729 .1.562 .2396 .3229 .4062 .4896 .5729 .6.562 .7396 .8229 .9062 .9896 

U .0755 .1.589 .2422 .3255 .4089 .4922 .5755 .6.589 .7422 .8255 .9089 .9922 



3229 


.4062 


.4896 


.5729 


.6.562 


.7396 


3255 


.4089 


.4922 


. 5755 


. 6589 


. 7422 


3281 


.4115 


.4948 


.5781 


.6615 


.7448 


S307 


.4141 


.4974 


.5807 


.6641 


.7474 



.0781 .1615 .2448 .3281 .4115 .4948 .5781 .6615 .7448 .8281 .9115 .9948 
.0807 .1641 .2474 .3307 .4141 .4974 .5807 .6641 .7474 .8307 .9141 .9974 
l.OOOO 



Table 27-00. Decimals of a Foot Equivalent to Inches and Fractions 

of an Inch 



Inches 


0" 


Vs" 


H" 


Vs" 


J4" 


%" 


H" 


Va" 








. 01042 


.02083 


.03125 


.04166 


. 05208 


.06250 


.07292 


1 


.0833 


.0937 


.1042 


.1146 


. 1250 


.1354 


.1459 


.1563 


2 


.1667 


.1771 


.1875 


.1979 


.2083 


.2188 


.2292 


.2396 


3 


.2500 


.2604 


.2708 


.2813 


.2917 


.3021 


.3125 


.3229 


4 


.3333 


.3437 


.3542 


.3646 


.3750 


3854 


.3958 


.4063 


5 


.4167 


.4271 


.4375 


.4479 


.4583 


.4688 


.4792 


.4896 


6 


.5000 


.5104 


.5208 


.5313 


.5417 


.5521 


.5625 


.5729 


7 


.5833 


.5937 


.6042 


.6146 


.6250 


.6354 


.6459 


.6563 


8 


.6667 


.6771 


.6875 


.6979 


.7083 


.7188 


.7292 


.7396 


9 


. 7500 


.7604 


.7708 


.7813 


.7917 


.8021 


.8125 


.8229 


10 


.83.33 


. 8437 


.8542 


.8646 


.8750 


.8854 


.89.58 


.9063 


11 


.9167 


.9271 


.9375 


.9479 


.9583 


.9688 


.9792 


.9896 



27—29 



Table 27-00. Mensuration of Surfaces and Volumes 

Area of rectangle = length X breadth. 
Area of triangle = base X H perpendicular height. 
Diameter of circle = radius X 2. 
Circumference of circle = diameter X 3.1416. 
Area of circle = square of diameter X .7854. 

area of circle X number of degrees in arc. 

Area of sector of circle = 

360 
Area of surface of cylinder = circumference X length + area of two ends. 

To find the diameter of circle having given area: Divide the area by .7854, and extract the square root. 
To find the volume of a cylinder: Multiply the area of the section in square inches by the length in inches 

= the volume in cubic inches. Cubic inches divided by 1728 = volume in cubic feet. 
Surface of a sphere = square of diameter X 3.1416. 
Solidity of a sphere = cube of diameter X .5236. 
Side of an inscribed cube = radius of a sphere X 1.1547. 
Area of the base of a pyrcunid or cone, whether round square or triangular, multiplied by one-third of its 

height = the sohdity. 
Diam. X .8862 = side of an equal square. 
Diam. X .7071. = side of an inscribed square. 
Radius X 6.2832 = circumference. 



Circumference = 3.5446 X V Area of circle. 



n 


= Proportion of circumference to 




diameter = 3.1415926. 


7r2 


= 9.8696044. 


V^ 


= 1.7724538. 


Log. JT 


= 0.49715. 


1/^ 


= 0.31831. 


1/360 


.002778. 


360/ ^ 


= 114.59. 



Dianeter = 1.1283 X V Area of circle. 

Leng h of arc = No. of degrees X .017453 radius. 

Degr es in arc whose length equals radius = 57° 2958'. 

Leng h of an arc of 1° = radius X .017543. 

Lcng h of an arc of 1 Min. = radius X .0002909. 

Length of an arc of 1 Sec. = radius X .0000048. 



Table 27-00. Electrical Units 

Volt — The unit of electrical motive force. Force required to send one ampere of current through one ohm 

of resistance. 
Ohm — Unit of resistance. The resistance offered to the passage of one ampere, when impelled by one volt. 
Ampere — Unit of current. The current which one volt can send through a resistance of one ohm. 
Coulc mb — Unit of quantity. Quantity of current which, impelled by one volt, would pass through one ohm 

in one second. 
Far ~ ft — Unit of capacity. A conductor or condenser which will hold one coulomb under the pressure of one 

volt. 
Joule — Unit of work. The work done by one watt in one second. 
Wa 1 1 — The unit of electrical energy, and is the product of ampere and volt. That is, one ampere of current 

flowing under a pressure of one volt gives one watt of energy. 
One electrical horsepower is equal to 746 watts. 
One Kilowatt is equal to 1,000 watts. 
To find the watts consumed in a given electrical circuit, such as a pump motor, multiply the volts by the 

amperes. 
To t nd the volts, divide the watts by the amperes. 
To fii.d the amperes, divide the watts by the volts. 

To find the electrical horsepower required by a motor, divide the watts of the motor by 746. 
To find the mechanical horsepower necessary to generate the required electrical horsepower, divide the latter 

by the efficiency of the generator. 
To find the amperes of a given circuit, of which the volts and ohms resistance are known, divide the volts by 

the ohms. 
To find the volts, when the amperes and watts are known, multiply the amperes by the ohms. 
To find the resistance in ohms, when the volts and amperes are known, divide the volts by the amperes. 



27—30 



Table 27-00. Circumferences and Areas of Circles 
Advancing by Eighths 



Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


A 


. 1909 


. 00019 


2 H 


8.4430 


5.6727 


7. 


21.991 


.38.485 


14 M 


44.768 


159.48 


A 


.09818 


. 00077 


M 


8.6394 


5.9396 


Ys 


22.384 


39.871 


Ys 


45.160 


162.30 




.14726 


.00173 


M 


8.8357 


6.2126 


Y 


22.776 


41.282 


Y2 


45.. 553 


165 13 


16 


.19635 


.00307 


% 


9.0321 


6.4918 


Ys 


23.169 


42.718 


Ys 


45.916 


167.99 




.29452 


. 00690 


M 


9.2284 


6.7771 


Y2 


23.. 562 


14.179 


Ya- 


46.338 


170.87 


Vs 


. 39270 


.01227 








Ys 


23.955 


45.664 


Ys 


46.731 


173.78 


^ 


.49087 


.01917 


3. 


9.4248 


7.0686 


Ya 


24.347 


47.173 








^ 


.58905 


. 02761 


1^ 


9.6211 


7.3662 


Yb 


24.740 


48.707 


15. 


47.124 


176.71 


-h 


. 68722 


.03758 


Vi 


9.8175 


7.6699 








Ys 


47.517 


179.67 








A 


10.014 


7.9798 


8. 


25.133 


50.265 


■Ya 


47.909 


182.65 


M 


. 78540 


.04909 


M 


10.210 


8.2958 


Ys 


25.. 525 


51.849 


Ys 


48.302 


185.66 


? 


.88357 


.06213 


_5_ 
16 


10.407 


8.6179 


Ya 


25.918 


53.456 


Y2 


48.695 


188.69 




.98175 


.07670 


Vs 


10.603 


8.9462 


Ys 


26.311 


55.088 


Ys 


49.087 


191.75 


Ji 


1.0799 


.09281 


A 


10.799 


9.2806 


Y2 


26.704 


56.745 


Ya 


49.480 


194.83 


% 


1.1781 


.11045 


K 


10.996 


9.6211 


Ys 


27.096 


58.426 


Ys 


49.873 


197.93 


H 


1.2763 


. 12962 


ii 


11.192 


9.9678 


Ya 


27.489 


60.132 








1% 


1.3744 


. 1.5033 


% 


11.388 


10.321 


Ys 


27.882 


61.862 


16. 


50.265 


201 . 06 


M 


1 . 4726 


. 17257 


ii 


11.585 


10.680 








Ys 


50.6.58 


204 22 








Ya 


11.781 


11.015 


9. 


28.274 


63.617 


Ya 


51.051 


207.39 


3^ 


1 . 5708 


.19635 


H 


11.977 


11.416 


Ys 


28.667 


65.397 


Ys 


51 . 414 


210.60 


¥ 


1 . 6690 


.22166 


V% 


12.174 


11.793 


Ya 


29.060 


67.201 


Y2 


51.836 


213.82 


16 


1.7671 


. 24850 


16 


12.370 


12.177 


Ys 


29.452 


69.029 


Ys 


52.229 


217.08 


if 


1.86.53 


. 27688 








Y2 


29.845 


70.882 


Ya 


52.622 


220.35 


\i 


1.9'i35 


. 30680 


4. 


12.566 


12.566 


Ys 


30.238 


72.760 


Ys 


53.014 


223.65 




2.0617 


. 33824 


A 


12.763 


12.962 


Ya 


30.631 


74.662 








16 


2.1598 


.37122 


y% 


12.959 


13.364 


Ys 


31.023 


76.589 


17. 


53.407 


226.98 


ft 


2.2580 


.40574 


A 


13.1.55 


13.772 








Ys 


53.800 


2.30.33 








¥ 


13.352 


14.186 


10. 


31.416 


78.540 


Ya 


54.192 


233.71 


M 


2.3.562 


.41179 


re 


13.548 


14.607 


Ys 


31.809 


80.516 


Ys 


54.585 


237.10 


14 


2.4544 


.4 937 


¥ 


13.744 


15.033 


Ya 


32.201 


82.516 


Y2 


54.978 


240.53 


13 
16 


2.5525 


.51819 


T6 


13.941 


15.466 


Ys 


32. .594 


84. 541 


Ys 


55.371 


213.98 


H 


2.6507 


. 5.5914 


¥ 


14 137 


15.904 


Y2 


32.987 


86. 590 


Ya 


55.763 


247.45 


J^ 


2.7489 


.60132 


Te 


14.334 


16.349 


Ys 


33.379 


88.664 


Ys 


56.156 


250.95 


ft 


2.8471 


. 6 1504 


y% 


14.530 


16.800 


Ya 


.33.772 


90.763 










2.94.52 


. 69029 


fi 


14.726 


17.257 


Ys 


34.165 


92.886 


18. 


56.549 


254.47 


|i. 


3.0434 


. 73708 


Ya 


14.923 


17.721 








Ys 


56.911 


2.58.02 








M 


15.119 


18.190 


11. 


.34. 558 


95.033 


Ya 


57.334 


261.59 


1. 


3.1416 


. 7854 


J-8 


15.315 


18 665 


Ys 


.34.950 


97.205 


Ys 


57.727 


265.18 


A 


3.3379 


.8866 


M 


15.512 


19.147 


Ya 


35.343 


99.402 


Y2 


.58.119 


268.80 


J^ 


3.5313 


.9940 








Ys 


35.736 


101.62 


Ys 


58.512 


272.45 


A 


3.7306 


1.1075 


5. ^ 


15.708 


19.635 


Y2 


36.1"8 


103.87 


Ya 


58.905 


276.12 


¥ 


3.9270 


1 2272 


fs 


15.901 


20.129 


Ys 


36.521 


106.14 


Ys 


59.298 


279.81 


16 


4.1233 


1 ' 3530 


Vi 


16.101 


20.629 


Y 


36.914 


108.43 








<? 


4.3197 


1.4849 


A 


16.297 


21.135 


Ys 


37.306 


110.75 


19. 


59.690 


283.53 


T6 


4.5160 


1.6230 


Va 


16.493 


21 . 648 








Ys 


60.083 


287.27 


M 


4.7124 


1 . 7671 


A 


16.690 


22 166 


12. 


.37.699 


113.10 


Ya 


60.476 


291 . 04 


i% 


4.9^87 


1.9175 


Y 


16.886 


22.691 


Ys 


38.09-! 


115.47 


Ys 


60.868 


294.83 


^ 


5.1051 


2.0739 


A 


17 082 


23.221 


Ya 


38 485 


117.86 


Y2 


61.261 


298.65 


H 


5.3914 


2.2365 


Vi 


17.279 


23.7.58 


Y 


38.877 


120.28 


Ys 


61 . 654 


302.49 


M 


5.4978 


2.4053 


A 


17.475 


24.301 


Y2 


39.270 


122.72 


Ya 


62.046 


306.35 


M 


5.6941 


2.5802 


Xi 


17.671 


24.850 


Ys 


39.663 


125.19 


Ys 


62.439 


310.24 


Vi 


5.8905 


2.7612 


Tt 


17.868 


25.406 


Ya 


40.0.55 


127.68 








re 


6.0868 


2.9483 


\a 


18.064 


25.967 


Ys 


40.448 


1.30.19 


20. 


62.832 


314.16 








T6 


18.261 


26.535 








Ys 


63.225 


318.10 


2. 


6.2832 


3.1416 


Y 


18.457 


27.109 


13. 


40.841 


132.73 


Ya 


63.617 


322.06 


16 


6.4795 


3.3410 


16 


18.653 


27.688 


Ys 


41.233 


135.30 


Y 


64.010 


326.05 


Ks 


6.6759 


3.5466 








Ya 


41 . 626 


137.89 


Y2 


64.403 


330.06 


tV 


6.8722 


3.7583 


6. 


18.850 


28.274 


Ys 


42.019 


140.50 


Ys 


64.795 


334.10 


M 


7.0686 


3.9761 


v% 


19.242 


29.465 


Yi 


42.412 


143.14 


Ya 


65.188 


338.16 


]^ 


7.2649 


4.2000 


Va 


19.635 


30.680 


Ys 


42.804 


145.80 


Ys 


65.581 


342.25 


¥ 


7.4613 


4.4301 


Ys 


20.028 


31.919 


Ya 


43.197 


148.49 








Te 


7.6576 


4.6664 


¥2 


20.420 


33.183 


Ys 


43.590 


151.20 


21. 


65.973 


346.36 


¥ 


7.8540 


4.9087 


Ys 


20.813 


34.472 








Ys 


66.366 


350.50 


16 


8.0503 


5.1.572 


Ya 


21.206 


35.785 


14. 


43.982 


153.94 


Ya 


66.759 


354.66 


^ 


8.2467 


5.4119 


Ys 


21 . 598 


37.122 


Ys 


44.375 


156.70 


Ys 


67.152 


358.84 



27—31 



Table 27-00. Circumferences and Areas of Circles 
Advancuig by Eighths — Continued 



Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


Diam. 


Circum. 


Area 


21 H 


67.511 


363,05 


28 H 


90.321 


619.18 


36. 


113.097 


1017,9 


43 Va 


135.874 


146'9,1 


Vs 


67.937 


367.28 


Vs 


90.713 


651.84 


Vs 


113. 190 


1025.0 


Vs 


136.267 


1477,6 


M 


68.330 


371 . 54 








Va 


113.883 


10.32.1 


V2 


136,659 


1486.2 


% 


68,722 


375.83 


29. 


91.106 


660. 52 


Vs 


114.275 


1039.2 


Vs 


137,052 


1494.7 








Vs 


91.499 


665.23 


V2 


114.668 


1046,3 


Va 


137,445 


1503,3 


22. 


69.115 


380.13 


M 


91.892 


671.96 


Vs 


115.061 


10.53.5 


Vs 


137.837 


1511.9 


Vi 


69.508 


381. 16 


Vs 


92,284 


677.71 


Va 


115.4.51 


1060,7 








Vi 


69.900 


388.82 


V2 


92,677 


683. 19 


Vs 


115.846 


1068,0 


44. 


138,230 


1520,5 


Vb 


70.293 


393.20 


Vs 


93,070 


689.30 








Vs 


138,623 


1529,2 


Vi 


70.686 


397,61 


H 


93,462 


691. 13 


37. 


116,239 


1075,2 


Va 


1.39.015 


1537,9 


Vs 


71.079 


402.04 


Vs 


93,855 


700.98 


Vs 


116.632 


1082,5 


Vs 


1.39. 108 


1546.6 


H 


71.471 


406.49 








Va 


117,024 


1089.8 


V2 


1.39.801 


1555.3 


Vs 


71.864 


410,97 


30. 


94,248 


705,86 


Vs 


117.417 


1097,1 


Vs 


140.194 


1564.0 








Vs 


94,640 


712,76 


V2 


117,810 


1104.5 


Va 


140.. 586 


1572,8 


23. 


72.257 


415,48 


M 


95,033 


718.69 


Vs 


118,202 


1111.8 


Vs 


140.979 


1581.6 


Vs 


72.649 


420,00 


Vs 


95,426 


721.64 


Va 


118. 596 


1119.2 








H 


73.042 


424.56 


V2 


95.819 


730.62 


Vs 


118.988 


1126,7 


45. 


141 . 372 


1.590,4 


Vs 


73.435 


429.13 


Vs 


96.211 


736.62 








Vs 


141,764 


1599,3 


K 


73.827 


433.74 


Va 


96,604 


742.64 


38, 


119.381 


1134.1 


Va 


142,1.57 


1608,2 


Vs 


74.220 


438.36 


Vs 


96.997 


748.69 


Vs 


119.773 


1141.2 


Vs 


142,. 5.50 


1617,0 


H 


74.613 


443.01 








Va 


120.166 


1149.2 


V2 


142,942 


1626,0 


Vs 


75.006 


447,69 


31. 


97.389 


751.77 


Vs 


120.559 


1156,6 


Vs 


143,3.35 


1634,9 








Vs 


97,782 


760.87 


V2 


120.951 


1164,2 


Va 


143,728 


1643,9 


24. 


75.398 


452,39 


Va 


98.175 


765.99 


Vs 


121 . 344 


1171,7 


Vs 


144,121 


1652,9 


Vs 


75.791 


457.11 


Vs 


98.567 


773.14 


Va 


121,737 


1179,3 








H 


76.184 


461.86 


V2 


98.960 


779 31 


Vs 


122,129 


1186,9 


46. 


144,513 


1661,9 


Vs 


76.576 


466.64 


Vs 


99.3.53 


785.51 








Vs 


144,906 


1670,9 


V2 


76.969 


471 . 44 


Va 


99.746 


791,73 


.39. 


122,. 522 


1194.6 


Va 


145,299 


1680,0 


Vs 


77.362 


476.26 


Vs 


100.138 


797,98 


Vs 


122.915 


1202.3 


Vs 


145.691 


1689,1 


% 


77.754 


481,11 








Va 


123.308 


1210.0 


Vi 


146.084 


1698,2 


Vs 


78,147 


485.98 


32. 


100.531 


801,25 


Vs 


123.700 


1217,7 


Vs 


146.477 


1707,4 








Vs 


100,924 


810,54 


V2 


124.093 


1225,4 


Va 


146.869 


1716.5 


25. 


78.540 


490 87 


Va 


101.316 


816,86 


Vs 


124,486 


1233,2 


Vs 


147,262 


1725.7 


Vs 


78.933 


495,79 


Vs 


101.709 


823.21 


Va 


124,878 


1241,0 








H 


79.325 


500,74 


V2 


102.102 


829.58 


Vs 


125,271 


1248,8 


47, 


147.655 


1734,9 


H 


79.718 


505.71 


Vs 


102.494 


835,97 








Vs 


148 018 


1744,2 


V2 


80 111 


510,71 


Va 


102.887 


842. 39 


10, 


125,664 


1256,6 


Va 


148.440 


1753.5 


Vs 


80 503 


515.72 


■ Vs 


103,280 


818,83 


Vs 


126.056 


1284,5 


Vs 


148.833 


1762.7 


H 


80.896 


520.77 








Va 


126.419 


1272,4 


V2 


119.226 


1772.1 


Vs 


81 . 289 


525.84 


33. 


103.673 


855.30 


H 


126.842 


1280.3 


Vs 


149.618 


1781,4 








Vs 


104.065 


861 , 79 


V2 


127.235 


1288,2 


Va 


150.011 


1790.8 


26. 


81.681 


530.93 


Va 


101.4,58 


858,31 


Vs 


127,627 


1296,2 


Vs 


150.404 


1800,1 


Vi 


82.074 


5.36.05 


Vs 


104,851 


871. 8 > 


Va 


128,020 


1304,2 








Vi 


82.467 


541.19 


Vi 


105,243 


881 . 41 


Vs 


128,413 


1312,2 


48. 


150,796 


1809,6 


Vs 


82.860 


546,35 


Vs 


105.636 


888.00 








Vs 


151,189 


1819,0 


V2 


83.252 


.551 . 55 


Va 


106.029 


894.62 


41. 


128.805 


1320.3 


Va 


151. 582 


1828,5 


Vs 


83.645 


556 . 76 


Vs 


106.421 


901.26 


Vs 


129.198 


1328,3 


Vs 


151.975 


1837,9 


% 


84 038 


562.00 








Va 


129. 591 


1336,4 


V2 


152.367 


1847.5 


Vs 


84.430 


567.27 


34. 


106.814 


907.92 


Vs 


129.983 


1344.5 


Vs 


152.760 


1857.0 








Vs 


107,207 


914.61 


V2 


130.376 


1352.7 


Va 


153,153 


1866,5 


27. 


84.823 


.572,56 


Va 


107,600 


921,32 


Vs 


130.769 


1360.8 


Vs 


153,545 


1876.1 


Vs 


85.216 


.577.87 


H 


107,992 


928 06 


Va 


131.161 


1369 








Va 


85.608 


583.21 


V2 


108. 385 


934 82 


Vs 


131,554 


1377,2 


49. 


153,938 


1885.7 


% 


86.001 


588.57 


Vs 


108.778 


941,61 








Vs 


154,331 


1895.4 


V2 


86 391 


593.96 


Va 


109.170 


918.42 


42. 


131,947 


1385,4 


Va 


154,723 


1905.0 


Vs 


86 786 


599.37 


Vs 


109,563 


955.25 


Vs 


132,340 


1393.7 


Vs 


155,116 


1914,7 


Vi 


87.179 


604,81 








Va 


132 732 


1402.0 


V2 


155,509 


1924.4 


Vs 


87 572 


610,27 


35. 


109.956 


952.11 


Vs 


133.125 


1410.3 


Vs 


155,902 


1934.2 








Vs 


110.348 


959.00 


V2 


1.33. 518 


1418.6 


Va 


156.294 


1943.9 


28 


87 965 


615.75 


Va 


110,741 


975 91 


Vs 


1,33,910 


1427.0 


Vs 


156.687 


1953.7 


Vs 


88.3.57 


621,26 


Vs 


111.131 


982 84 


Va 


134,303 


1435.4 








K 


88.7.50 


626,80 


V% 


111.527 


989 80 


Vs 


134.696 


1443,8 


50. 


157,080 


1963.5 


Vs 


89.143 


632,36 


Vs 


111.919 


995 78 














V2 


89.535 


637,94 


Va 


112, 312 


1000.38 


43. 


135,088 


1452.2 








Vs 


89,928 


643,55 


Vs 


112.705 


1010,8 


Vs 


135.481 


1460.7 









'11— Zl 



Table 27-00. Fractional Equivalents, Powers, Roots and Velocity Heads of 

Numbers 



Num- 
ber 


Frac. 
Equiv 


Square 
Root 


Cube 
Root 


Square 


Cube 


■o 
» 

■s 


d 


Num- 
ber 


Frac. 
Equiv 


Square 
Root 


Cube 
Root 


Square 


Cube 


3 

w 


1 

H 














l> 














> 


> 


.01 
,0156 
.02 
.03 


64 


.1 

.125 
. 141 1 
.1732 


.2154 

.25 

,2714 

,3107 


.0001 
. 0002441 
.0004 
.0009 


. 000001 
. 000003815 
. 000008 
. 000027 


.802 
1.003 
1.134 
1.389 


.3281 
.33 
34 
3438 




.5728 
. 57 15 
. 5831 
.5863 


.6897 
.6910 
.6980 
.7005 


.1077 
.1089 
.1156 
.1182 


. 03533 
. 03.594 
. 03930 
. 04062 


4. 594 

4.607 
4.677 
4.702 


.0313 
.04 
.0169 
.05 


32 


.1768 
2 

!2165 
.2236 


. 3150 
, 3420 
.3606 
,3684 


. 0009766 
.0016 
. 002197 
.0025 


. 00003052 
. 000064 
.000103 
.000125 


1.418 
1.604 
1.756 
1.793 


.35 
3594 
.,36 
.37 


li 


.5916 
.5995 
.6 
.6083 


. 7047 
.7110 
.7114 
.7179 


. 1225 
.1292 
.1296 
.1369 


. 04288 
. 04641 
. 04666 
.05065 


4.745 
4.808 
4.812 
4.879 


.06 
.0625 
.07 
.0781 




,2449 
.25 
,2646 
.2795 


,3915 
,3968 
.4121 
.4275 


.0036 
. 003906 
.0049 
.006104 


.000216 
.0002441 
.000343 
. 0004768 


1.965 
2.005 
2 122 

2^242 


.375 
.38 
.39 
.3906 


% 

25 
64 


.6124 
.6164 
. 6245 
.625 


.7211 
. 7243 
.7306 
.7310 


.1406 
. 1444 
.1521 
.1526 


.05273 
.05487 
. 05932 
.05960 


4.911 

4.944 
5.009 
5.013 


.08 
.09 
.0938 
.1 


32 


.2828 
.3 

.3062 
.3162 


.4309 
.4181 
.4543 
.4642 


. 0064 
.0081 
. 008789 
.01 


.000512 
. 000729 
. 0008240 
.001 


2.269 
2.406 
2.4.56 
2.537 


.4 

.4063 

.41 

.42 


13 


.6325 
. 6374 
.6403 
. 6481 


.7368 
. 7406 
. 7429 
.7489 


.16 
. 1650 
.1681 
.1764 


.64 

. 06705 
. 06892 
. 07409 


5.072 
5.112 
5.135 
5.198 


.1094 
.11 
.12 
.125 


6T 


.3307 
.3317 
. 3464 
.3536 


.4782 
. 4791 
.4932 
.5 


.01196 
.0121 
.0144 
. 01562 


.001308 
.001331 
.001728 
.001953 


2.653 
2.660 
2.778 
2.836 


.4219 
.43 
.4375 
.44 


64 


. 6495 
. 6557 
.6614 
.6633 


.75 
.7548 
.7591 
.7606 


.1780 
.1849 
.1914 
.1936 


. 07508 
.07951 
. 08374 
.08518 


5.209 
5.259 
5.305 
5.320 


.13 
.14 
.1406 
.15 


64 


.3606 
. 3742 
.375 
,3873 


.5066 
.5193 
. 5200 
.5313 


.0169 
.0196 
.01978 
.0225 


. 002197 
. 002744 
. 002781 
.003375 


2.892 
3.001 
3.008 
3.106 


.45 
.4531 
.46 
. 4688 




.6708 
.6732 
.6782 
.6847 


.7663 
.7681 
.7719 
.7768 


. 2025 
.2053 
.2116 
.2197 


.09113 
. 09304 
. 09734 
.1030 


5.380 
5.399 
5.440 
5.491 


.1563 
.16 
.17 
.1719 




,3953 
.4 

.4123 
,4146 


.5386 
.5429 
. 5540 
.5560 


. 02441 
. 0256 
.0289 
.02954 


. 003815 
. 004096 
.004913 
.005077 


3.170 
3.208 
3.307 
3.325 


.47 
.48 
. 4844 
.49 


67 


.6856 
.6928 
.6960 

.7 


.7775 
.7830 
.7853 
.7884 


.2209 
.2304 
.2346 
.2401 


.1038 
.1106 
.1136 
.1176 


5.498 
5.557 
5.582 
5.614 


.18 
.1875 
.19 
.20 


'^ 


.4243 

,433 

.4359 

.4472 


. 5646 
.5724 
.5749 
. 5848 


. 0324 
. 03516 
.0361 
.04 


. 005832 
. 006592 
. 006859 
.008 


3.403 
3.473 
3.496 
3.587 


.5 
.51 
.5156 
.52 


'A 

33 


.7071 
. 7141 
.7181 
.7211 


.7937 
.7990 
.8019 
.8042 


.25 
.2601 
.2658 
.2704 


.125 
.1327 
.1371 
.1406 


5.671 
5.728 
5.759 
5.784 


.2031 

.21 

.2188 

.22 




,4507 
.4583 
.4677 
.4690 


. 5878 
. 59 14 
.6025 
.6037 


. 04126 
. 04 11 
. 04785 
.0484 


. 008381 
. 009261 
. 01047 
.01065 


3.615 
3.675 
3.751 
3.762 


.53 
.5313 
.54 
.5469 




.7280 
.7289 
. 7349 
.7395 


.8093 
.8099 
.8143 
.8178 


.2809 
.2822 
.2916 
.2991 


.1489 
. 1499 
. 1575 
.1636 


5.839 
5.846 
5.894 
5.931 


.23 
. 2344 
.24 
.25 


64 


.4796 
.4841 
.4899 
.5 


.6127 
.6165 
.6215 
.6300 


.0529 
. 05493 
.0576 
.0625 


.01217 
.01287 
.01382 
.01563 


3.846 
3.883 
3.929 
4.010 


.55 
.56 
. 5625 

.57 


9 
16 


.7416 
.7483 

.75 
.7550 


.8193 
. 8243 
.8255 
.8291 


.3025 
.3136 
. 3164 
.3249 


.1664 
.1756 
.1780 
.1852 


5.948 
6.002 
6.015 
6.055 


.26 
.2656 

.27 
.28 


ii 


.5099 
. 5154 
. 5196 
.5292 


.6383 
.6428 
. 6463 
.6542 


.0676 
. 07056 
.0729 
.0784 


.01758 
.01874 
.01968 
.02195 


4.090 
4.134 
4.167 
4.244 


.5781 
.58 
.59 
. 5938 


11 


.7603 
.7616 
.7681 

. 7706 


.8330 
.8340 
. 8387 
. 8405 


.3342 
.3364 
. 3481 
.3525 


.1932 
.1951 
.20.54 
.2093 


6.098 
6.108 
6.161 
6.180 


.2813 
.29 
.2969 
.30 


^ 

M 


.5303 
.5385 
. 5448 

.5477 


. 6552 
.6619 
.6671 
.6694 


. 07910 
.08U 
.08814 
.09 


02225 
. 02439 
. 02617 
.027 


4.253 
4.319 
4.370 
4.393 


.6 

.6094 
.61 
.62 


H 


.7746 
.7806 
.7810 
.7874 


. 8434 
. 8478 
.8481 
.8527 


.36 
.3713 
.3721 
.3844 


.2160 
.2263 
.2270 
.2383 


6.212 
6.261 
6.264 
6.315 


.31 

.3125 

.32 


A 


.5568 
.5590 
.5657 


.6768 
.6786 
. 6840 


. 0961 
. 09766 
.1024 


.0-2979 
. 03052 
. 03277 


4.466 
4.483 
4.537 


.625 

.63 

.64 


Vb 


.7906 
.7937 
.8 


. 8550 
.8573 
.8618 


.3906 
.3969 
. 4096 


.2441 
.2500 
.2621 


6.341 
6.366 
6.416 



27—33 



Table 27-00. Fractional Equivalents, Powers, Roots and Velocity Heads of 

Numbers — Continu ed 



Num- 
ber 


Frac. 
Equiv 


Square 
Root 


Cube 
Root 


Square 


Cube 


s 


i 

H 

o 


Number 


Frac. 
Equiv 


Square 
Root 


Cube 
Root 


Square 


Cube 


1 
& 
















I> 
















> 


.6406 


a 


.8004 


.8621 


.4104 


.2629 


6.419 


.96 




.9798 


.9865 


.9216 


. 8847 


7.8.58 


.65 




.8062 


.8662 


.4225 


.2746 


6.466 


.9688 


M 


.9843 


.9895 


.9385 


.9091 


7.894 


.6563 


ji 


.8101 


.8690 


.4307 


.2826 


6.497 


.97 




. 9849 


.9899 


.9409 


.9127 


7.899 


.66 




.8124 


.8707 


.4356 


.2875 


6.516 


.98 




. 


.9899 


.9933 


.9604 


.9412 


7.940 


.67 




.8185 


.8750 


.4489 


.3008 


6.565 


.9844 


1 


1 


.9922 


.9948 


.9690 


.9538 


7.9.57 


.6719 


ii 


.8197 


.8759 


.4514 


.3033 


6.574 


.99 






.9950 


.9967 


.9801 


.9703 


7.980 


.68 




.8246 


.8794 


.4624 


.3144 


6.614 


1. 






1. 


1. 


1. 


1. 


8,021 


.6875 


ii 


.8292 


.8826 


.4727 


.3249 


6.650 


1.1 






1 . 049 


1.032 


1.21 


1.331 


8.412 


.69 




.8307 


. 8837 


.4761 


.3285 


6,662 


1.2 






1.095 


1.063 


1.44 


1.728 


8.786 


.70 




.8367 


.8879 


.49 


. 3430 


6.710 


13 






1.14 


1.091 


1.69 


2.197 


9.145 


.7031 


45 
64 


.8395 


.8892 


.4944 


.3476 


6.725 


1.4 






1.183 


1.119 


1.96 


2.744 


9.490 


.71 




.8426 


.8921 


. 5041 


.3579 


6.758 


1.5 






1.225 


1.1145 


2.25 


3.375 


9.823 


.7188 


M 


. 8478 


.8958 


.5166 


.3713 


6.799 


1.6 






1.265 


1.170 


2.56 


4.096 


10,14 


.72 




. 8485 


.8963 


.5184 


.3732 


6.805 


1.7 






1.304 


1.193 


2.89 


4913 


10.45 


.73 




. 85 14 


. 9004 


.5329 


.3890 


6.8.53 


1.8 






1.342 


1.216 


3.24 


5.832 


10.76 


.7344 


ti 


.8570 


.9022 


.5393 


.3961 


6.873 


1.9 






1.378 


1.239 


3.61 


6.859 


11.06 


.74 




.8602 


.9045 


.5476 


.40.52 


6.899 


2. 






1.414 


1.260 


4. 


8. 


11,34 


.75 


% 


.8660 


.9086 


. 5625 


.4219 


6.946 


2.1 






1 . 449 


1.281 


4.41 


9.261 


11,62 


.76 




.8718 


.9126 


.5776 


.4390 


6.992 


2.2 






1.483 


1.301 


4.84 


10.65 


11.90 


.7656 


49 
64 


.875 


.9148 


.5862 


.4488 


7.018 


2^3 






1.517 


1.320 


5.29 


12.17 


12,16 


.77 




.8775 


.9166 


.5929 


.4565 


7.038 


2.4 






1.549 


1.339 


5.76 


13.82 


12.43 


.78 




.8832 


.9205 


.6084 


.4746 


7.083 


2.5 






1.581 


1 . 357 


6.25 


15.63 


12.68 


.7813 


25 
32 


. 8839 


.9210 


.6104 


.4768 


7.089 


2.6 






1.612 


1.375 


6.76 


17.58 


12.93 


.79 




.8888 


.9244 


.6241 


. 4930 


7.129 


2.7 






1.643 


1.392 


7.29 


19.68 


13.18 


.7969 


a 


.8927 


.9271 


. 6350 


.5060 


7.159 


2.8 






1.673 


1.409 


7.84 


21.95 


13,42 


.8 




.8944 


.9283 


.64 


. 5120 


7.174 


2.9 






1.703 


1 . 426 


8.41 


24.39 


13,66 


.81 




.9 


.9322 


.6561 


.5314 


7.218 


3. 






1.732 


1.442 


9 


27. 


13,89 


.8125 


H 


.9014 


.9331 


.6602 


.5364 


7.229 


3.1 






1.761 


1.458 


9.61 


29.79 


14.12 


.82 




.9055 


.9360 


.6724 


.5514 


7.263 


3.2 






1.789 


1.474 


10.24 


32.77 


14,35 


.8281 


n 


.9100 


.9391 


.6858 


.5679 


7.298 


3.3 






1.817 


1.489 


10.89 


35.94 


14.57 


.83 




.9110 


.9398 


.6889 


.5718 


7.307 


3.4 






1.844 


1.504 


11.56 


39.30 


14 79 


.84 




.9165 


.9435 


.7056 


.5927 


7.351 


3.5 






1.871 


1.518 


12.25 


42.88 


15,01 


.8438 


27 
32 


.9186 


.9449 


.7120 


.6007 


7.367 


3.6 






1.897 


1.533 


12.96 


46.66 


15.22 


.85 




.9219 


.9473 


.7225 


.6141 


7.394 


3.7 






1.924 


1.547 


13.69 


50.65 


15.43 


. 8594 


fi 


.9270 


. 9507 


.7385 


.6347 


7.435 


3.8 






1.949 


1.560 


14.44 


54.87 


15.64 


.86 




.9274 


.9510 


.7396 


.6361 


7.438 


3.9 






1.975 


1.574 


15.21 


59.32 


15.85 


.87 




.9327 


.9546 


.7569 


.6585 


7.481 


4. 






2 


1.587 


16. 


64. 


16.04 


.875 


Vs 


.9354 


.9565 


.7656 


.6699 


7.502 


4.1 






2.025 


1.601 


16.81 


68.92 


16.24 


.88 




.9381 


.9583 


.7744 


.6815 


7.524 


4.2 






2.049 


1.613 


17.64 


74.09 


16.44 


.89 




.94.34 


.9619 


.7921 


.7050 


7.566 


4.3 






2.074 


1.626 


18.49 


79.51 


16.63 


.8906 


a 


.9437 


.9621 


.7932 


.7065 


7.569 


4.4 






2.098 


1.639 


19.36 


85.18 


16,82 


.9 


. 


. 9487 


.9655 


.81 


.7290 


7.609 


4.5 






2.121 


1.651 


20.25 


91.13 


17,01 


.9063 


32 


.9520 


.9677 


.8213 


.7443 


7.635 


4.6 






2.145 


1.663 


21.16 


97.34 


17,20 


.91 




.9539 


.9691 


.8281 


.7536 


7.651 


4.7 






2.168 


1.675 


22.09 


103.8 


17,39 


.92 




. 9592 


.9726 


. 8464 


.7787 


7.693 


4.8 






2.191 


1.687 


23.04 


110.6 


17.57 


.9219 


fi 


.9601 


.9732 


.8499 


.7835 


7.701 


4.9 






2.214 


1.698 


24.01 


117.6 


17,75 


.93 




.9644 


.9761 


. 8649 


.8044 


7.734 


5. 






2.236 


1.710 


25. 


125. 


17.93 


.9375 


15. 


.9682 


.9787 


.8789 


.8240 


7.766 
















.94 




.9695 


.9796 


.8836 


.8306 


7.776 
















.95 




.9747 


.9831 


.9025 


.8574 


7.817 
















.9531 


64 


.9763 


.9840 


.9084 


.8659 


7.830 

















27—34 



Long Measure 
12 inclies = l foot. 

3 feet = 1 y!>r.l 

5 1-2 yards = 1 rod. 

4 rods = 1 chain. 

10 chains = 1 furlong, 
li furlongs = 1 mile. 



Table 27-00. Measures of Weight, Capacity and Area 

Cubic Measure 
1728 cubic inches = 1 cubic foot. 



Square Measure 
144 .square inches = 1 square foot. 
9 square iVet = l square yard. 
30 % square yards = 1 square rod. 
160 square rods = l acre. 
640 acres = 1 square mile. 



27 cubic feet = l cubic yard. 
24.75 cubic feet = 1 perch. 
128 cubic feet = 1 cord. 



Liquid Measure 
4 gills = 1 pint. 
2 pints = 1 quart. 
4 quarts = 1 gallon. 
31 J'^ gallons = 1 barrel. 
2 barrels = 1 hogshead. 



Avoirdupois Wciglit 
16 ounces = 1 pound. 
100 pounds = 1 hundredweight. 
20 cwt. = 1 ton. 



Table 27-00. Comparison of Wire Gauges 



1 


Sis. 


MP 

n 


a 

o 




II 


T3 d 


1 


?, oil 

•It 


E 
MS 


a 

i 






•o a 






A 
$ 


S^ 






1 


1?^ 
o 


s 


.d 
1 


I» 


J2 




0000000 






.490 


.500 




.500 


23 


. 02257 


.025 


.02.58 


.024 


.027 


. 028125 


000000 


. 5800 




.460 


. 464 




.46875 


24 


.02010 


.022 


. 0230 


.022 


.025 


.025 


00000 


. 5165 




.430 


.432 




.4375 


25 


.01790 


.020 


. 0204 


.020 


.023 


.021875 


0000 


.4600 


.4.54 


.3938 


.400 


.454 


. 40625 


26 


.01594 


.018 


.0181 


.018 


.0205 


. 01875 


000 


.4096 


.425 


. 3625 


.372 


.425 


.375 


27 


. 01420 


.016 


.0173 


.0164 


.0187 


.0171875 


00 


.3648 


.380 


.3310 


.348 


.38 


. 34375 


28 


. 01264 


.014 


.0162 


.0148 


.0165 


.015625 





.3249 


.340 


.3065 


. 324 


.34 


. 3125 


29 


.01126 


.013 


.0150 


.0136 


.0155 


. 0140625 


1 


.2893 


.300 


.2830 


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